adj. & n.
--adj.
1. a of or like a question; used in questions. b Gram. (of an adjective or pronoun) asking a question (e.g. who?, which?).
2 having the form or force of a question.
3 suggesting enquiry (an interrogative tone).
--n. an interrogative word (e.g. what?, why?).
Derivatives:
interrogatively adv.
Etymology: LL interrogativus (as INTERROGATE)