questionnaire n.

late 15c., questiounen, "to inquire, ask, seek to know," from question (n.) and from Old French questioner "ask questions, interrogate, torture" (13c.), from question (n.). Hence "to dispute, doubt," by 1530s. Transitive sense of "inquire of by asking questions" is from late 15c. Related: Questioned; questioning. Alternative verb questionize is attested from 1847.

adjective and noun word-forming element, in most cases from Latin -arius, -aria, -arium "connected with, pertaining to; the man engaged in," from PIE relational adjective suffix *-yo- "of or belonging to." The neuter of the adjectives in Latin also were often used as nouns (solarium "sundial," vivarium, honorarium, etc.). It appears in words borrowed from Latin in Middle English. In later borrowings from Latin to French, it became -aire and passed into Middle English as -arie, subsequently -ary.