c. 1200, "to be lacking," from Old Norse vanta "to lack, want," earlier *wanaton, from Proto-Germanic *wanen, from PIE *weno-, suffixed form of root *eue- "to leave, abandon, give out." The meaning "desire, wish for, feel the need of" is recorded by 1706.
c. 1200, "deficiency, insufficiency, shortage," from want (v.) and from Old Norse vant, neuter of vanr "wanting, deficient;" related to Old English wanian "to diminish" (see wane). Meaning "state of destitution, poverty" is recorded from early 14c. Meaning "thing desired, that which is lacking but needed" is from 1560s. Phrase for want of is recorded from c. 1400. Newspaper want ad is recorded from 1897. Middle English had wantsum (c. 1200) "in want, deprived of," literally "want-some."