Proto-Indo-European root meaning "to protect." It forms all or part of: conservation; conservative; conserve; observance; observatory; observe; preserve; reservation; reserve; reservoir.

It is the hypothetical source of/evidence for its existence is provided by: Avestan haurvaiti "to guard;" Latin servare "to guard, keep, watch;" Old Church Slavonic xraniti "to guard, protect;" Old High German gi-sarwi "armor, equipment," Old English searu "art, skill; wile, deceit."