Is it ensure, insure, or assure?
c.1600, from French posture (16c.), from Italian postura "position, posture," from Latin positura "position, station," from postulus, past participle of ponere "put, place" (see position (n.)).
1620s, literal, from posture (n.). The figurative sense of "take up an artificial mental position" is attested from 1877. Related: Postured; posturing.
posture pos·ture (pŏs'chər)
A position of the body or of body parts.
A characteristic or prescribed way of bearing one's body; carriage.