quiddity

When it comes to synonyms of quiddity, the Q's have it. Consider quintessence, a synonym of the "essence of a thing" sense of quiddity (this oldest sense of quiddity dates from the 14th century). Quibble is a synonym of the "trifling point" sense; that meaning of quiddity arose from the subtler points of 16th-century academic arguments. And quirk, like quiddity, can refer to a person's eccentricities. Of course, quiddity also derives from a "Q" word, the Latin pronoun quis, which is one of two Latin words for "who" (the other is qui). Quid, the neuter form of quis, gave rise to the Medieval Latin quidditas, which means "essence," a term that was essential to the development of the English quiddity.