preserve: [14] The -serve of preserve comes from Latin servāre ‘keep safe’ (no relation to servīre ‘serve’, but source also of English conserve, observe, and reserve). Combination with prae- ‘before’ produced medieval Latin praeservāre ‘guard beforehand, take steps to ward off possible harm’, which reached English via Old French preserver. => conserve, observe, reserve[preserve etymology, preserve origin, 英语词源]