(grammar) Asking or denoting a question: as, an interrogative phrase, pronoun, or point. / Pertaining to inquiry; questioning

(grammar) A word (pronoun, pronominal adjective, or adverb) implying interrogation, or used for asking a question: why, who, when, etc. / (typography, archaic) Synonym of question mark ⟨?⟩.

plural of interrogative

In an interrogative manner; by means of a question.

Interrogatability.

That can be interrogated; that can respond to a query.

plural of interrogator

The act of interrogating or questioning; examination by questions; inquiry. / A question put; an inquiry. / (dated) A question mark.

(transitive) to question or quiz, especially in a thorough and/or aggressive manner / (transitive, computing) to query; to request information from. / (transitive, literary) to examine critically.

simple past tense and past participle of interrogate