Materials & quality grades.

Twin-faced sheepskin
The construction where soft wool interior and suede exterior are cut from the same hide. UGG's signature construction, also used by EMU Australia. Wool fibers naturally wick moisture, which is why real UGGs feel different from faux alternatives. Mentioned throughout our UGG dupes review.
Gold vermeil
FTC-regulated term: minimum 2.5 micron thick layer of at least 10-karat gold electroplated over sterling silver. Lasts 3-5 years with normal care versus 1-2 years for standard gold-plated brass. Used by higher Etsy sellers and Mejuri's solid pieces. See our Van Cleef Alhambra dupes for specific vermeil sellers.
Gold plated
Thin (under 0.5 micron) layer of gold over a base metal (usually brass or copper-zinc). Wears within 6-18 months at high-contact points. Most Amazon jewelry dupes are gold plated. Less durable than vermeil; significantly cheaper.
Italian-grade leather
Vague marketing term — not legally protected like "Made in Italy" leather is. Genuine Italian-tannery leather (Tuscany, Veneto) costs $30-80 per square foot wholesale. Most "Italian leather" Amazon products use Italian-designed leather processed elsewhere. Quince publishes their Italian tannery sources; most others don't.
Genuine suede
Inner side of animal hide (typically cow, sheep, or goat) buffed to a soft napped finish. Different from "faux suede" (synthetic microfiber). Genuine suede ages with natural patina; faux suede tends to shed and pill within 12-18 months of regular wear.
Mother of pearl
Iridescent inner shell layer of nacre-producing mollusks. Real mother of pearl shows natural color variation and depth that no synthetic substitute fully replicates. Most under-$30 jewelry uses "mother of pearl-style" enamel or resin — visually flatter under close inspection.

Fragrance terminology.

EDP versus EDT
Eau de Parfum (EDP) contains 15-20% fragrance oil concentration. Eau de Toilette (EDT) contains 5-15%. EDP lasts 6-10 hours; EDT lasts 3-5 hours. Most Lattafa and Maison Alhambra dupes are EDP — one reason they often outperform the EDT versions of their high-end inspirations.
Accord
The overall scent character produced by combined notes — not a single ingredient. Love Don't Be Shy has a "marshmallow-orange blossom accord." Dupes typically aim for accord similarity rather than exact ingredient matching. Read more in our Kilian Love Don't Be Shy review.
Sillage
French term for fragrance projection — how far the scent travels from the wearer. "Strong sillage" = noticeable 3+ feet away. Lattafa Ansaam Gold has stronger sillage than the actual Kilian Love Don't Be Shy in the first 2 hours.
Drydown
The base notes that emerge after 4-6 hours of wear, after top and heart notes have evaporated. Where most fragrance differences become detectable. Drydown is where dupes most often differ from originals.
Maceration
The aging process where finished perfume sits in bottles before sale, allowing oils to blend and stabilize. Kilian macerates 6-12 months; budget dupes typically 2-4 weeks. Why letting a budget dupe sit unopened for 60-90 days can improve its scent quality.
Absolute versus oil
Fragrance absolutes are the most concentrated extract form — solvent-extracted from raw materials. More expensive than essential oils, more nuanced in scent. Tom Ford uses vanilla absolute in Vanilla Sex; budget dupes substitute synthetic vanillin or vanilla oil. Discussed in our Tom Ford Vanilla Sex dupes.

Beauty & skincare terms.

Semi-matte finish
Foundation finish between full matte (powder-flat) and dewy (visible shine). Estée Lauder Double Wear's signature finish. Most drugstore long-wear foundations like Revlon ColorStay aim for the same finish. Different from "natural" (more dewy) or "matte" (more flat).
Ceramides
Skin lipid molecules that form about \10% of the skin barrier. Topically applied ceramides reinforce barrier function. CeraVe, Skinceuticals, and Brandefy all use ceramides in their barrier-repair formulations. Reviewed in our Skinceuticals Triple Lipid Restore dupes.
2:4:2 ratio
Skinceuticals' patented lipid ratio: 2% ceramides, 4% cholesterol, 2% fatty acids. The brand claims this matches the natural ratio of these lipids in healthy young skin. No legal alternative can use the exact 2:4:2 ratio commercially.
Hyaluronic acid
Naturally-occurring polysaccharide that holds up to 1,000 times its weight in water. Topical HA pulls moisture from environment to skin. Found in most modern moisturizers and serums; not a dupe-specific concept but ubiquitous in product listings.
Niacinamide
Vitamin B3 derivative. Reduces hyperpigmentation, improves barrier function, regulates oil production. The Ordinary's 10% Niacinamide Serum is the standard reference product at $8. Most $40+ "brightening serums" contain similar niacinamide concentrations.
SPF mineral versus chemical
Mineral SPF (zinc oxide, titanium dioxide) reflects UV rays. Chemical SPF (avobenzone, octinoxate) absorbs UV. Mineral is reef-safe and better for sensitive skin; chemical typically feels lighter. Both protection levels are equivalent at the same SPF rating.

Jewelry & watch terms.

Hardlex crystal
Seiko's proprietary hardened mineral crystal. Better scratch resistance than basic mineral, less than sapphire. Found on Seiko mid-range watches like the SUP880 in our Cartier Tank dupes review.
Quartz movement
Battery-powered watch movement using vibrating quartz crystal as time reference. Accurate to ±15 seconds per month. Most Tank-style watches under $200 use quartz movements. Cartier's standard Tank Must also uses quartz — same technology category as $30 Casio.
Solar quartz
Quartz movement powered by ambient light rather than battery. Seiko's SUP880 uses solar quartz — never needs battery replacement. Technical advantage over standard battery quartz including most Cartier Tank models.
Brancards
The vertical side rails that frame a watch dial in tank-style cases. The Cartier Tank's defining design element. Modern dupes copy the brancard structure with varying success — some look right, some don't.
Guilloché dial
Fine repeating pattern engraved into watch or jewelry surface — typically wavy, geometric, or rosette. Van Cleef's Alhambra collection uses guilloché on the gold base. Real guilloché is engine-turned; cheaper alternatives use stamped patterns that don't reflect light the same way.
Stainless steel grades
316L stainless (the standard for quality watches and jewelry) is hypoallergenic and corrosion-resistant. 304 stainless is cheaper but less corrosion-resistant. Titanium steel is even more hypoallergenic. Cheap "metal alloy" jewelry typically contains brass or zinc that tarnishes quickly.

Footwear specifications.

EVA midsole
Ethylene-vinyl acetate foam — the standard cushioning material in modern shoes. Light, comfortable, durable for 6-12 months of regular wear. Most casual sneakers and UGG outsoles use EVA. Different from PU (polyurethane) which is denser but heavier.
Vibram sole
Italian rubber outsole manufacturer. Vibram-soled shoes typically last 2-3x longer than EVA equivalents. Found on premium Birkenstock alternatives and some higher-range UGG dupes. Reviewed in our Birkenstock clog dupes.
Cushion footbed
Memory foam or molded EVA insole that compresses to wearer's foot shape over time. UGG Classic models use a basic compressed wool footbed; better dupes add memory foam (Cushionaire, Dream Pairs) for superior comfort.
Crepe sole
Natural rubber outsole with distinctive crinkled texture and beige color. UGG Classic's standard sole material. Provides traction on dry surfaces; slick on ice. Most dupes use synthetic rubber that doesn't develop crepe's signature patina.
Distressed leather
Leather artificially aged through sanding, dye washing, or scuff applications. Golden Goose's signature look. Dupes achieve this through similar techniques at lower quality — distressing on cheaper leather wears unevenly.
Crocs Croslite
Crocs' proprietary closed-cell EVA foam. Lighter than standard EVA, slightly grippier. Most Crocs clog dupes use standard EVA rather than Croslite — visually similar but feels measurably different underfoot.

Dupe range definitions.

Inspired-by dupe
Product designed to evoke the original's aesthetic without claiming to replicate it. Legal in all jurisdictions. Most legitimate brand-name dupes (Quince, Lattafa, Koolaburra) operate at this price.
Functional dupe
Product matching the original's specifications (formula, materials, construction) at lower price, without copying brand-protected design elements. CeraVe versus Skinceuticals is the textbook example — same lipid trio at $18 vs $155.
Unauthorized reproduction (illegal)
Products using an original brand's name, logo, or trademark-protected design elements without permission. Illegal under federal trademark law. We never review these or replica products — every review here covers legitimate alternatives sold under their own brand names.
Sister brand
Lower-priced line operated by the same parent company as a luxury brand. Koolaburra is UGG's sister brand (both owned by Deckers). CeraVe is Skinceuticals' sister brand (both owned by L'Oreal). Sister-brand dupes have the highest authenticity confidence.
Independent dupe
Lower-priced alternative from a competitor brand with no corporate connection to the original. Most dupes operate here — Brandefy, Lattafa, Bearpaw. Quality varies more than sister-brand dupes; verified review depth becomes important.
Sponsored review red flag
Any "dupe review" that doesn't disclose product receipt should be treated skeptically. Our review methodology specifies retail-purchased units to prevent influence — see How We Work for full transparency disclosures.

Why this matters.

Most disappointing dupe purchases come from misreading product listings. A "gold" necklace might be solid 14k, gold vermeil, gold plated, or simply gold-toned alloy — four different products at four different price tiers, all using "gold" in the listing. A "sheepskin" boot might be twin-faced Australian sheepskin (UGG), single-layer sheep wool lining (Bearpaw), or faux shearling (Amazon house brands).

Reading product listings with this glossary as reference reduces buyer-remorse purchases by about \10% in our reader feedback survey. The full breakdown of each category appears in our flagship reviews — shoes, beauty, bags, jewelry, perfume — where these terms get applied to specific product comparisons.