QUIDDITY Meaning of QUIDDITY in English n. (pl. -ies) 1 Philos. the essence of a person or thing; what makes a thing what it is. 2 a quibble; a trivial objection. [ med.L quidditas f. L quid what ] Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012