TRADEMARK, also trade mark, trademark.
1. A SIGN or NAME that is secured by legal registration or (in some countries) by established use, and serves to distinguish one product from similar brands sold by competitors: for example, the shell logo for Shell, the petroleum company, and the brand name Jacuzzi for one kind of whirlpool bath. Legal injunctions are often sought when companies consider that their sole right to such marks has been infringed; the makers of Coke, Jeep, Jell-O, Kleenex, Scotch Tape, and Xerox have all gone to court in defence of their brand (or proprietary) names. Although companies complain when their trademarks begin to be used as GENERIC terms in the media or elsewhere, their own marketing has often, paradoxically, caused the problem.

There is in practice a vague area between generic terms proper, trademarks that have become somewhat generic, and trademarks that are recognized as such. The situation is complicated by different usages in different countries: for example, Monopoly and Thermos are trademarks in the UK but generics in the US. Product wrappers and business documents often indicate that a trademark is registered by adding TM (for ‘trademark’) or R (for ‘registered’) in a superscript circle after the term, as with English Today™, Sellotape.® The term usually differs from trade name by designating a specific product and not a business, service, or class of goods, articles, or substances: but some trademarks and trade names may happen to be the same. Everyday words of English that were once trademarks (some now universal, some more common in one variety of English than another, some dated, all commonly written without an initial capital) include aspirin, band-aid, cellophane, celluloid, cornflakes, dictaphone, escalator, granola, hoover, kerosene, lanolin, mimeograph, nylon, phonograph, shredded wheat, zipper. Trademarks facing difficulties include Astroturf, Dacron, Formica, Frisbee, Hovercraft, Jacuzzi, Laundromat, Mace, Muzak, Q-Tips, Scotch Tape, Styrofoam, Teflon, Vaseline, Xerox. The inclusion of such names in dictionaries, even when marked ‘trademark’ or ‘properietary term’, indicates that their status has begun to shift. Trademark names used as verbs are a further area of difficulty, both generally and in lexicography. One solution adopted by publishers of dictionaries is to regard the verb forms as generic, with a small initial letter: that is, Xerox (noun), but xerox (verb).

2. A mark or feature characteristic of, or identified with, a person or thing: That slow drawl is his trademark.