late 14c., from Old French inquisitif, from Late Latin inquisitivus "making inquiry," from Latin inquisit-, past participle stem of inquirere "seek after, search for; examine, investigate" (see inquire).
An housbonde shal nat been Inquisityf of goddes pryuetee nor of his wyf. [Chaucer, "Miller's Prologue"]
Related: Inquisitively; inquisitiveness.
In Church history, inquisitors were appointed from 382 C.E. to root out heretics; the ecclesiastical court appointed 13c. by Innocent III to suppress heresy never operated in Britain. The English word began to be used in this sense (and with a capital initial letter) after c. 1500, and usually refers to the office's reorganization 1478-1483 in Spain, where it fell under the control of the state as what is commonly called the Spanish Inquisition, noted especially for its severity, secrecy, and the number of its victims.
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.