9 letters · 18 points in Scrabble
adjective using the name of one thing for that of another with which it is closely associated
originFrom Ancient Greek μετωνυμικός (metōnumikós, “of or like metonymy”), from μετωνυμία (metōnumía, “change of name”), from μετά (metá, “other”) + ὄνυμα (ónuma, “name”). By surface analysis, metonym + -ic.
Etymology from Wiktionary, CC BY-SA 3.0