Origins
The word 'wool' is one of the oldest and most important words in the English language from the standpoint of historical linguistics. It descends, through an unbroken chain of transmission, from a Proto-Indo-European root that is among the most confidently reconstructed in the entire PIE vocabulary: *h₂wĺ̥h₁neh₂ (wool). The existence of this word in the proto-language is powerful evidence that the PIE-speaking peoples were pastoralists who kept domesticated sheep and processed their fleece — a conclusion that aligns with archaeological evidence placing PIE origins in the steppe regions north of the Black Sea around 4000–3000 BCE.
Old English 'wull' comes from Proto-Germanic *wullō, which regularly descends from the PIE form. The cognates span the entire Indo-European family: Latin 'lāna' (wool), which produced French 'laine,' Spanish 'lana,' and the English scientific term 'lanolin' (literally 'wool oil'); Greek 'lēnos' (wool); Sanskrit 'ūrṇā' (wool); Lithuanian 'vilna' (wool); Old Church Slavonic 'vlŭna' (wool); Welsh 'gwlân' (wool). The forms look strikingly different on the surface — English 'wool,' Latin 'lāna,' Sanskrit 'ūrṇā' — but the sound correspondences are regular and well understood. The initial *h₂w- was preserved in Germanic as /w/ but lost in Italic and Greek; the internal laryngeal *h₁ was lost everywhere but left traces in vowel coloring; the *-n- appears in Latin, Lithuanian, and Slavic but was modified in Germanic.
Within Germanic, the cognates are straightforward: German 'Wolle,' Dutch 'wol,' Old Norse 'ull' (the /w/ was lost in Norse), Swedish and Norwegian 'ull,' Danish 'uld,' and Gothic 'wulla' all descend from Proto-Germanic *wullō.
Development
Wool was the single most important textile fibre in medieval and early modern Europe. In England, the wool trade was the foundation of national prosperity for centuries. The Lord Chancellor still sits on the 'Woolsack' in the House of Lords — originally a large sack of wool placed in the chamber during the reign of Edward III (1327–1377) as a symbol of England's wealth. The Cotswolds, East Anglia, and Yorkshire built their magnificent medieval churches on wool profits. The English wool trade with Flanders was a primary driver of Anglo-French diplomacy and conflict throughout the Middle Ages.
The word generated numerous compounds and derivatives in English. 'Woolen' (made of wool) dates from Old English. 'Woolly' (resembling wool, or figuratively, unclear in thinking) appears in the sixteenth century. 'Dyed in the wool' (thoroughly ingrained, unchangeable) comes from the textile practice of dyeing raw wool before spinning, which produced a more permanent colour than dyeing finished cloth. 'To pull the wool over someone's eyes' (to deceive) may allude to pulling a wig (originally made of wool-like material) down over someone's face.
The PIE root *h₂wĺ̥h₁neh₂ belongs to a cluster of pastoral vocabulary terms that linguists use to reconstruct the PIE economy and way of life. Alongside words for 'sheep' (*h₃ówis), 'cow' (*gʷṓws), 'horse' (*h₁éḱwos), 'yoke' (*yugóm), and 'wheel' (*kʷékʷlos), the word for 'wool' helps establish that the PIE speakers were semi-nomadic pastoralists who had domesticated several animal species, practiced textile production, and used wheeled vehicles. The word 'wool,' in other words, is not just a name for a fibre — it is a glimpse of the daily life of a prehistoric culture that existed six thousand years ago.
Latin Roots
The contrast between 'wool' (the Germanic reflex) and 'lanolin' (from the Latin reflex 'lāna') in modern English illustrates a common pattern: everyday, domestic words tend to come from the Germanic layer of English vocabulary, while scientific and technical terms come from the Latin-Greek layer. We wear 'wool' sweaters but apply 'lanolin' cream — two words from the same prehistoric root, reunited in the same language after thousands of years of separate development.