What speakers mean by it now
In current English, want is first a verb of desire. People want a meal, want to leave, or want someone else to answer. A second layer still shows in stock phrases: to want for nothing, for want of evidence, and found wanting. Those formulas talk about absence or shortfall, not appetite. As a noun, want can still mean poverty or a missing necessity, though that use now sounds formal or literary beside the everyday verb of wishing.
The two layers are not accidents of style. They are successive meanings of the same loan. The wishing sense is the latecomer.
A Norse verb of lack
English did not inherit this particular verb from Old English. It came in from early Scandinavian during the long contact that followed Norse settlement in Britain. Middle English has wanten, first recorded in the late twelfth century. The earliest firm evidence is around 1175 in the Ormulum, where the form is wannte. Later medieval spellings include wante, wonten, and, in Scots, vant.
The source is Old Norse vanta, a weak verb meaning to lack or to be missing. In Old Norse the verb was typically impersonal: both the person and the thing stood in the accusative, closer to it lacks someone something than to modern I want. Middle English kept a shadow of that pattern. Constructions such as him wanteth could mean he lacks, with the person marked as if the lack were happening to him rather than as a wish he was forming.
The loan is widely accepted, though historical dictionaries sometimes hedge with probably, because the match is morphological and geographic rather than a single documented import. Modern Icelandic, Faroese, and Norwegian still have verbs of this shape with the older sense of being without. English kept the sound and, for a long time, the meaning.
Native English already had relatives in the same family. Old English wana meant lack or deficiency. The verb wanian, to diminish, is the ancestor of wane. The adjective wan meant deficient and only later came to mean pale. What English borrowed from Norse was not the idea of emptiness. It borrowed a ready-made verb built on that idea.
Roots, suffixes, and cousins
Behind vanta, linguists reconstruct a Proto-Germanic verb, often written wanatōną, from a noun wanô, lack or deficiency. The t in the Norse verb is a derivational suffix. It is not the same ending as the neuter adjective vant, the neuter of vanr, deficient, even though those forms sit in one family. The noun want in English likely has a mixed origin: conversion from the verb, and influence from that Norse neuter adjective.
How far back the story goes depends on the handbook. Some etymologies attach the word to a Proto-Indo-European root written euə- or eue-, with a sense of leaving, abandoning, or giving out, and derivatives that mean empty or lacking. Other reconstructions write h₁weh₂- and gloss it simply as empty. The labels differ; the cluster of meanings does not. Sanskrit una-, deficient, Avestan va-, lack, Armenian unain, empty, and Latin vanus, empty, and vacare, to be empty, are often placed here. That is why vacant, vacuum, vain, and void sit at a distance from want without looking like English cousins at first glance.
Inside Germanic the relatives are easier to see. Middle High German wan meant not full. Middle Dutch wan meant empty or poor. English still carries the prefix wan- in a few fossil compounds. Wanton belongs in the same neighborhood: historically it is wan- plus a word for trained or brought up, so undisciplined rather than eager. The family is one of shortfall. Appetite is a later English overlay.
How lack learned to desire
For centuries after the loan, speakers used want to say that something was missing. A thing could want, meaning it was absent or not forthcoming. A person could want courage, meaning they did not have it. That intransitive use, something wants, has been rare since the seventeenth century and now sounds archaic, except in the still-current participle wanting, missing or inadequate.
The noun moved in parallel. Around 1200 it meant deficiency. By the early fourteenth century it could mean destitution: to live in want. The phrase for want of is in place by about 1400. In the sixteenth century the noun can name the thing that is lacking but needed. None of these steps requires wishing. They describe a gap.
The gap invited a further move. If you lack something you need, you may also feel the need of it. By the early eighteenth century, sources record want as to desire or wish for; one dating given for that sense is 1706. After that, the new meaning crowded out the old in ordinary speech. Today I want a drink is almost never heard as I lack a drink, except as a joke that leans on the older sense. Need, lack, and miss took over the work of naming absence. Want kept the work of naming appetite.
A late offshoot sits in classified advertising. The want ad, recorded in the 1890s, is a notice for something desired, not a bulletin about shortage in the abstract. The newspaper sense only makes sense once the verb has already shifted from hole to wish.
What the cousins still show
A concrete check on the history is to set English beside its living North Germanic relatives. Icelandic vanta still means to lack. English took the same loan and taught it to name a wish. That is why found wanting still judges a shortfall, while I want this names a desire that may have nothing to do with poverty. The origin of the word want is a Scandinavian verb of deficiency; the modern everyday sense is an English afterthought, only about three centuries old.