Origins
The word 'sheep' descends from Old English 'scēap,' a word whose ultimate origin is one of the minor mysteries of Germanic linguistics. While the word is solidly attested in the West Germanic languages — German 'Schaf,' Dutch 'schaap,' Low German 'Schaap' — it is conspicuously absent from North Germanic (Swedish, Norwegian, Danish, and Icelandic all use 'får,' from Proto-Germanic *fæhaz) and from Gothic. This restricted distribution suggests that *skāpan is a West Germanic innovation rather than an inherited Proto-Germanic word.
Where *skāpan came from is debated. One proposal connects it to a verb meaning 'to create' or 'to shape' (compare German 'schaffen'), the idea being that the sheep was 'the created or shaped one' — perhaps referring to selective breeding or the shaping of wool. Another theory suggests borrowing from a pre-Indo-European substrate language of northwestern Europe, which might explain the word's limited distribution. No theory has won consensus.
What makes the sheep particularly interesting linguistically is that it replaced the original Indo-European word. PIE *h₃éwis (sheep) is one of the most widely attested animal names in the family: Latin 'ovis' (giving English 'ovine'), Greek 'óis,' Sanskrit 'ávi,' Lithuanian 'avis,' Old Church Slavonic 'ovĭca,' Old Irish 'oí.' In English, this ancient root survives only in the learned adjective 'ovine' and in 'ewe' (Old English 'ēowu'), which denotes specifically an adult female sheep and descends from a related PIE form *h₃éwi-. So while the general word was replaced, the feminine-specific term survived — a curious split.
Old English Period
The Old English plural of 'scēap' was 'scēap' — unchanged from the singular. This zero-plural pattern, which persists in modern English ('one sheep, two sheep'), is a relic of Old English neuter noun inflection, where certain nouns had identical nominative singular and plural forms. The same pattern survives in 'deer,' 'fish' (in collective use), 'swine,' and 'moose' — often in animal names, which may reflect a conceptual tendency to treat herd animals as a mass rather than as individuals.
Sheep held enormous economic importance in medieval England and thus feature prominently in the language. The wool trade was the backbone of the English economy from the 12th through 16th centuries, and the Lord Chancellor still sits on the Woolsack in the House of Lords, a symbol dating to the reign of Edward III in the 14th century, when England's wealth was built on sheep's backs. This economic centrality ensured that the vocabulary of sheep-rearing was rich and detailed in English: 'ewe' (adult female), 'ram' or 'tup' (adult male), 'lamb' (young sheep), 'wether' (castrated male), 'hogg' or 'hogget' (yearling), 'shearling' (after first shearing), 'flock' (the group), 'fold' (the enclosure), 'shepherd' (the keeper).
The word 'mutton' for sheep meat, like 'beef' for cow meat and 'pork' for pig meat, came from Old French ('moton,' from Medieval Latin 'multō'), illustrating the post-Conquest linguistic stratification where English named the living animal and French named the food.
Middle English
The figurative use of 'sheep' for docile, easily led people is ancient, appearing in biblical texts and classical literature. 'The Lord is my shepherd' (Psalm 23) establishes the sheep-as-follower metaphor that permeates Christian discourse. 'Sheepish,' meaning embarrassedly timid, is attested from the early 13th century. 'Black sheep' for a family disgrace dates to the 18th century, reflecting the lower commercial value of dark-wooled sheep.
The word 'shepherd' itself (Old English 'scēaphyrde,' literally 'sheep-herd') is one of the oldest compound words in English. Its antiquity reflects the antiquity of the practice: sheep were among the earliest domesticated animals, tamed from the wild mouflon (Ovis orientalis) in Mesopotamia around 10,000 years ago. By the time the Germanic-speaking peoples needed a word for the animal, it had been a domesticated companion of human civilization for millennia.
The etymology of 'sheep' thus presents a paradox: a word of uncertain, possibly non-Indo-European origin became the standard term in the language of a nation whose wealth and identity were inseparable from the animal it named. Whatever its ultimate source, 'sheep' earned its place in English by sheer economic and cultural indispensability.