- oust
- 1420, from Anglo-Fr. oster (1292), from O.Fr. oster "put out, keep off, remove, avert" (Fr. ๔ter), from L. obstare "stand opposite to, block, hinder," from ob "against" + stare "to stand," from PIE base *sta- "to stand" (see stet). Ouster (n.) is first recorded 1531, noun use of Anglo-Fr. ouster.