What's the "een" in Halloween?
1901, from French questionnaire "list of formal questions," from questionner "to question," (see question (v.)). Purists preferred native formation questionary (1540s); cf. -ary.
questionnaire ques·tion·naire (kwěs'chə-nâr')n. A printed form containing a set of questions, especially one addressed to a statistically significant number of subjects as a way of gathering information for a survey.