Harm
Old English hearm (noun), hearmian (verb), of Germanic origin; related to German Harm and Old Norse harmr ‘grief, sorrow’.
wiktionary
From Middle English harm, herm, from Old English hearm, from Proto-West Germanic *harm, from Proto-Germanic *harmaz(“harm; shame; pain”).
etymonline
harm (n.)
Old English hearm "hurt, pain; evil, grief; insult," from Proto-Germanic *harmaz (source also of Old Saxon harm, Old Norse harmr "grief, sorrow," Old Frisian herm "insult; pain," Old High German harm, German Harm "grief, sorrow, harm"), from PIE *kormo- "pain." To be in harm's way is from 1660s.
harm (v.)
Old English hearmian "to hurt, injure," from the noun (see harm (n.)). It has ousted Old English skeþþan (see scathe (v.)) in all but a few senses. Related: Harmed; harming.