doom (n.)

Old English dom "law, judgment, condemnation," from Proto-Germanic *domaz (source also of Old Saxon and Old Frisian dom, Old Norse domr, Old High German tuom, Gothic doms "judgment, decree"), from PIE root *dhe- "to set, place, put, do" (source also of Sanskrit dhaman- "law," Greek themis "law," Lithuanian domė "attention"). A book of laws in Old English was a dombec. Modern sense of "fate, ruin, destruction" is c. 1600, from the finality of the Christian Judgment Day.

doom (v.)

late 14c., from doom (n.). The Old English word was deman, which became deem. Related: Doomed; dooming.