Quiddity

Part of speech: noun (n.)

1. The essence, nature, or distinctive peculiarity, of a thing; that which answers the question, Quid est or, What is it " The degree of nullity and quiddity." Bacon. The quiddity or characteristic difference of poetry as distinguished from prose. De Quincey.

2. A trifling nicety; a cavil; a quibble. We laugh at the quiddities of those writers now. Coleridge.