quiddity

1 an odd or peculiar habit for all of her quiddities, she is a very wise and generous lady Synonyms crotchet, curiosity, eccentricity, erraticism, individualism, kink, mannerism, oddity, peculiarity, idiosyncrasy, quip, quirk, singularity, tic, trick, twistRelated Words affectation, airs; attribute, characteristic, mark, property, trait; custom, habit, pattern, practice (also practise), way, wont; addiction; abnormality, neuroticism, perversion, weirdness; disposition, genius, leaning, partiality; bent, inclination, penchant, predilection, predisposition, proclivity, propensity, tendency, turn; attitude, character, humor, identity, individuality, nature, personality, temperamentNear Antonyms conformity, sameness

2 the quality or qualities that make a thing what it is Rembrandt's genius was his unparalleled ability to render a person's quiddity in a single portrait Synonyms being, essentiality, nature, essence, quintessence, soul, stuff, substanceRelated Words heart, spirit; alpha and omega, center, core, keynote, marrow, pith, seat; embodiment, epitome, incarnation, manifestation, personification; aspect, attribute, feature, property; gist, kernel, nub