/bʊl/
[noun] An adult male animal of the cattle family, known for its strength and sometimes aggressive behaviour. The word is also used more broadly to describe something large, powerful, or forceful.
The word 'bull' likely came to English from Viking invaders — the Anglo-Saxons had a completely different word for the animal.
Long before the word 'bull' arrived in English, the Anglo-Saxons used an entirely different term for the adult male ox: 'fearr', a word of ancient Germanic stock that has since vanished entirely from the language. When the Vikings began settling in Britain during the 9th and 10th centuries, they brought their own vocabulary with them, and their Old Norse word 'boli' — meaning a male bovine — gradually shouldered the older Anglo-Saxon term aside. By the time Middle English was taking shape in the 11th and 12th centuries, 'bole' and then 'bull' had become the dominant form, and 'fearr' was quietly forgotten.
The Old Norse 'boli' itself belonged to a large family of Germanic words all connected to the idea of swelling, roundness, or physical power. Scholars trace it back to a Proto-Germanic root '*bullon-', which carried the sense of something that bellows or swells up. This same root is the distant ancestor of other English words: Proto-Germanic '*bullon-' → Old English 'bellan' (to roar) → modern 'bellow', and separately Proto-Germanic '*bul-' → Middle Dutch 'bolle' → the concept of a rounded, bulging form that gives us 'bulge' and even 'ball'. The bull, in the eyes of the ancient Germanic peoples, was above all a creature defined by its noise and its physical enormity.
The word expanded rapidly beyond the farmyard. By the 14th century, 'bull' was being used figuratively to describe any man of exceptional size or brute strength. The financial world later adopted the term: by the early 18th century, a 'bull' on the stock market was someone who bought shares expecting prices to rise — pushing the market upward, as a bull thrusts with its horns — as opposed to a 'bear', who expected a fall. This pairing became one of the most durable pieces of financial slang in the English language, still used on trading floors worldwide.
There is also a completely separate 'bull' lurking in the English language — the papal bull, an official decree issued by the Pope. This word has no connection whatsoever to the bovine animal. It comes from Latin 'bulla', meaning a rounded seal or stamped medallion, which was attached to important documents to authenticate them. Latin 'bulla' → Medieval Latin 'bulla' (official seal, then the document itself) → Middle English 'bulle'. The Latin 'bulla' also gave us 'bulletin' (Latin 'bulla' → Italian 'bullettino', a small note or certificate → French 'bulletin' → English 'bulletin') and 'bullet' (Latin 'bulla' → Old French 'boule', a ball → Old French 'boulette', a small ball → Middle French 'boulet' → English 'bullet'). The two bulls — the animal and the papal decree — are false friends who have shared the same spelling for centuries.
In informal speech, 'bull' took on yet another layer of meaning. By the early 20th century, particularly in American English, 'bull' became a colourful way of saying nonsense or dishonest talk. This usage is almost certainly a polite shortening of a far more vulgar compound noun describing the waste product of the animal, though some scholars suggest it may also owe something to the older tradition of describing loud, blustering speech as 'bull-roaring'. Whatever its exact origin, this sense of the word spread rapidly through colloquial English and remains vigorous today.
What makes 'bull' so remarkable is not any single meaning but the sheer number of unrelated threads that have knotted themselves around the same four letters. An animal name borrowed from Viking settlers, a financial metaphor born in 18th-century London coffeehouses, a papal seal from medieval Latin, and a piece of 20th-century slang — all sharing one short, forceful syllable. Few words in English carry so many entirely different histories inside such a small package.