Problematic; open to doubt or challenge. / Of dubious respectability or morality. / (obsolete) Inviting questions; inviting inquiry.

(transitive) To ask questions of; to interrogate; to ask for information. / (transitive) To raise doubts about; have doubts about.

A sentence, phrase or word which asks for information, reply or response; an interrogative. / A subject or topic for consideration or investigation.

plural of question

Third-person singular simple present indicative form of question

A game in which players must only say questions, and if they don't they lose.

in a questionable manner

The state of being questionable.

(rare, dated) questioning; full of questions

Without a doubt; certainly.