pus: [16] English borrowed pus from Latin pūs, which was descended from the prehistoric Indo- European base *pū- (source also of English foul and Latin puter ‘rotten’, from which English gets putrid [16]). Its stem form pūr- has given English purulent [16] and suppurate [16]. The Greek relative of Latin pūs was púon ‘pus’, from which English gets pyorrhoea [18]. => foul, purulent, putrid, pyorrhoea, suppurate[pus etymology, pus origin, 英语词源]