*gheim-

Proto-Indo-European root meaning "winter." 

It forms all or part of: chimera; chiono-; hiemal; hibernacle; hibernal; hibernate; hibernation; Himalaya.

It is the hypothetical source of/evidence for its existence is provided by:  Sanskrit heman "in winter;" Hittite gimmant-, Armenian jmern, Greek kheima, Latin hiems, Old Church Slavonic zima, Lithuanian žiema "winter;" Greek khion "snow."