A comparative we use every day
In present-day English, less marks a smaller amount, degree, or extent. It sits in front of mass nouns (less water), grades other words (less likely, less carefully), and stands alone as a noun or pronoun when the thing being reduced is already clear (I want less). It can also work as a preposition with the sense minus: the salary, less tax. Its usual partner on the other side of the scale is more. That job looks simple. The history is a native Germanic comparative that English later assigned to little, a word it does not actually come from.
How English already had it
The origin of the word less is inheritance, not borrowing. Old English already used an adverb lǣs and an adjective lǣssa (Northumbrian leassa) for smaller, fewer, and to a smaller degree. Those forms moved through Middle English as les, lesse, leasse, and lasse, then settled as less. The written record in English reaches back before the year 900. Nothing in that path looks like a later French or Latin loan; the word was Germanic before it was English.
The Old English pair is already a comparative, not a positive adjective that later grew an ending. Behind it stands Proto-Germanic *laisizan (adverb *laisiz), a stem for small plus a comparative suffix. West Germanic relatives keep the same idea: Old Saxon and Old Frisian les, and an Old Frisian adjective lessa. German leise, meaning soft or quiet, and Middle Dutch lise, gentle, are usually placed on the same branch, even though their meanings have drifted from size toward softness of sound or manner.
The older root, and two lookalikes
Further back, etymological dictionaries reconstruct a Proto-Indo-European root often written *leis- or *leys-, with a sense around small. A Baltic cognate is Lithuanian liesas, thin or lean. The exact Indo-European shape is not settled. Some later work prefers a northern reconstruction *leh₂is- or *leh₃is-. That disagreement is real; the Germanic comparative itself is not in doubt.
What is easy to miss is that less is not a form of little. Little comes from Old English lytel, from a different Germanic stem, *lutilla-, probably tied to a different Indo-European base. English simply uses less and least as the comparative and superlative of little, the same kind of mix-and-match pattern as good, better, best. An older dictionary tradition sometimes folded both words into a vague *lei- root meaning diminish or meager. Current references keep the stems apart.
The suffix in hopeless is another false relative. English -less comes from Old English -lēas, without, a word related to loose, not to the adverb lǣs. Spelling has made the two look like one family. They are not.
The genuine relatives of less are the extra comparatives English stacked on the same stem. Least is the old superlative: Old English læst, earlier læsest, from a Germanic superlative *laisista-. Lesser, from the early thirteenth century, is a double comparative, less plus the ordinary -er ending. Critics later called the extra -er inelegant; the form survived in lesser-known and the lesser of two evils. Lest, for fear that, is a contraction of Old English þȳ lǣs þe, the less that, reduced in Middle English to leste. Unless grew from Middle English on lesse, on a less compelling condition, with the first syllable later heard as un-.
What the meaning did, and did not, do
The core sense has been stable for as long as English has written the word: smaller in amount, size, number, or degree. From the beginning the adverb liked negative company, which is why none the less and nonetheless still feel natural. Much less in the sense still more undesirable is recorded from the 1630s.
One sense has almost vanished. Less could once mean younger, used to render Latin minor. That reading is dead in ordinary speech and survives mainly as a fossil in the biblical name James the Less. An old verb less, to make smaller, existed beside the now usual lessen; it is archaic.
The modern quarrel over less versus fewer is newer than the vocabulary. Usage guides often want fewer with countable things and less with mass nouns. Historical English did not keep that split. Old English lǣs already covered both fewer and less, and writers have used less with plural count nouns for more than a thousand years. Shop signs that say ten items or less follow an old pattern, not a recent slip. Less than before measures of time, money, and distance is equally established.
As a preposition, less took on the arithmetic meaning minus, not including. Dialect has also used it as a clipped unless since the early fifteenth century, later stretched in some American speech to lessen or less'n.
A fossil in a name
If you want one concrete remnant of a lost sense, James the Less is it: a comparative that once meant the younger or the lesser in rank, still sitting in a proper name after everyday English moved on. The word itself never had to be imported. Speakers have been using this Germanic comparative of small, in one spelling or another, since the Old English period. Only later did it become the official partner of little, a neighbor in the dictionary and a stranger in the family tree.