What English still means by drink
English drink covers two tightly related ideas. As a verb it names the act of taking liquid into the mouth and swallowing it. As a noun it names the liquid itself, a serving of that liquid, and, in a narrower modern use, an alcoholic beverage or the habit of taking one. That last sense is so familiar that a sentence such as they drink can mean they consume alcohol, not that they swallow water. The word also stretches: people drink in a view, drink to a friend's health, or fall into the drink, meaning the sea.
The origin of the word drink is native, not a loan from French or Latin. It was already ordinary English before the Norman Conquest.
Old English, not a later import
Speakers of Old English used the strong verb drincan. It belonged to class III, with a past tense dranc and a past participle druncen, the ancestors of drank and drunk. The core sense was to swallow water or another fluid. The same verb could also mean to swallow something up or engulf it, so the idea of taking liquid in sat beside a darker picture of being taken in by liquid.
The noun is just as old. Late Old English has drinc and drync for a beverage or a draught, formed from the verb rather than borrowed beside it. Standard historical dictionaries treat both verb and noun as inherited from Germanic and first recorded in the Old English period, that is, before 1150.
A small sound-history note explains why the noun looks like the verb. The Old English noun drinc would, in southern dialects, have been expected to yield something like drinch, the same palatal outcome that produced drench. The verb kept a k sound, and the noun followed the verb, so Modern English has drink for both parts of speech.
A Germanic family, and a German shift
The Old English verb continues Proto-West Germanic drinkan and Proto-Germanic drinkaną (sometimes reconstructed drenkanan). This is inheritance across the North Sea, not a medieval import. Close relatives still look familiar: Dutch drinken, Old Saxon drinkan, Old Frisian drinka (West Frisian drinke), Old Norse drekka, Swedish dricka, Danish drikke, and Gothic drigkan. Scots kept drink as well.
High German is the odd one out in appearance, not in meaning. Old High German trinkan and modern German trinken begin with t because of the High German consonant shift, which turned many Germanic d sounds into t. The words are still the same verb. German also preserves a related noun Getränk for a beverage, built on the same root.
How far back the trail goes
Beyond Germanic, the trail grows thin. Major historical dictionaries stop at further etymology unknown. Scholars have long guessed at a root meaning to draw, as if drinking were drawing liquid into the mouth. Some Indo-European dictionaries and reconstructions of Proto-Germanic point to a form dʰreǵ- (often cited as dhreg-), to draw or glide, with a nasalized variant dʰrenǵ- for sipping or gulping. Possible extra-Germanic relatives sometimes offered for that root include Lithuanian drėgti, to become moist, and Sanskrit dhrájati, to glide. Those links are not agreed. It is honest to treat the Indo-European step as a hypothesis, not a settled pedigree.
One contrast is solid. Most other Indo-European languages built their ordinary drink-verb on a different root, reconstructed po(i)-. That family gives Greek pínō, Latin bibere (and English imbibe through French and Latin), Old Irish ibid, Old Church Slavonic piti, and Russian pit'. Germanic speakers kept drinkaną instead. English later borrowed imbibe, potion, and potable from the other lineage, so the two ancient roots now sit side by side in the same vocabulary.
Causative twin: drench
Old English also had drencan, a causative: to give someone drink, ply them with liquor, soak them, even drown them. It comes from a Proto-Germanic causative drankijaną, formed with the same -janą suffix that produced pairs such as sit and set, lie and lay, fall and fell. Sound change turned drencan into Middle English drenchen and modern drench. For a time drench could mean to drown. By the sixteenth century the dominant sense was to wet thoroughly. The veterinary drench, a liquid forced down an animal's throat, still remembers the older idea of making someone drink.
Old English multiplied the simple verb with prefixes: gedrincan (drink, consume, drown), bedrincan (drink up, absorb), fordrincan (drink to excess), oferdrincan (overdrink). Those compounds show that swallowing, soaking, drowning, and drunkenness were already a tight semantic cluster a thousand years ago. The later English adjectives drunk and drunken grow out of the same participle that once sat beside drincan.
How the senses moved
The physical meaning never left. What changed is how far the word wandered from the cup.
By the late twelfth century English used drink figuratively for taking something in through the senses. By the mid-thirteenth century people could drink to someone as a salute in a toast. From the mid-fifteenth century the verb is especially at home with spirituous liquor: to drink can mean to take alcohol, and the noun often means an alcoholic drink rather than any beverage. Around 1300 the noun also settles as a quantity, as much as is taken at one time.
Later English added idioms rather than new roots. Drink like a fish is recorded from the eighteenth century; drink someone under the table from the early twentieth. Slang the drink for the sea treats a large body of water as the ultimate liquid. None of these is a new etymology. They are the old verb and noun doing extra work.
A leftover that still explains the pair
The useful takeaway is not a reconstructed Indo-European syllable, which may or may not be right, but a living English pair. Drink is what you do. Drench is what used to mean making someone else do it. German still keeps a clearer version of that split: trinken to drink, tränken to water an animal or give drink. English hid the causative under a palatal consonant and then let its meaning slide from forcing a draught to soaking a coat. The two words are still siblings. One kept the cup. The other kept the wet.