Cachet

Etymology
From cachet.

Noun

 * 1) A special characteristic or quality.
 * I remember when this diner was a quiet hangout, but lately it seems to be losing its cachet.
 * 1)  A seal, as of a letter.

Synonyms

 * charm, je ne sais quoi, magic touch, oomph, zing

Thesaurus
aroma, attribute, badge, billhead, book stamp, bookplate, brand, broad arrow, cast, character, characteristic, check, colophon, configuration, counterfoil, countermark, cut, differentia, differential, dignity, distinction, distinctive feature, docket, earmark, feature, figure, flavor, government mark, government stamp, gust, hallmark, identification, idiocrasy, idiosyncrasy, importance, impress, impression, imprint, index, individualism, keynote, label, letterhead, lineaments, logo, logotype, mannerism, mark, marking, masthead, mold, nature, odor, particularity, peculiarity, plate, prestige, price tag, prominence, property, quality, quirk, registered trademark, running head, running title, savor, seal, shape, sigil, signet, singularity, smack, specialty, stamp, sticker, stub, tag, taint, tally, tang, taste, ticket, title page, token, trade name, trademark, trademark name, trait, trick