1325-75; (v.) Middle English < Latinconservāre to save, preserve, equivalent to con-con- + servāre to watch over, guard (akin to servus slave, servīre to serve); (noun) Middle English < Middle Frenchconserve, noun derivative of conserver < Latin, as above
late 14c., from Old French conserver (9c.), from Latin conservare "to keep, preserve, keep intact, guard," from com-, intensive prefix (see com-), + servare "keep watch, maintain" (see observe). Related: Conserved; conserving. As a noun (often conserves) from late 14c.