From PIE *h₂wlh₁neh₂ — one of the most securely reconstructed words, proving ancient IE wool-working.
The fine, soft, curly hair forming the coat of a sheep, goat, or similar animal, used in making cloth or yarn.
From Old English 'wull,' from Proto-Germanic *wullō, from PIE *h₂wĺ̥h₁neh₂ (wool, fleece). This is one of the most securely reconstructed and widely attested PIE words, with cognates in nearly every branch of the family: Latin 'lāna' (wool, whence 'lanolin'), Greek 'lēnos' (wool), Welsh 'gwlân' (wool), Lithuanian 'vìlna' (wool), Russian 'volna' (wave, but originally fleece), and Sanskrit 'ūrṇā' (wool). The word's universality across the family shows that wool-working — shearing, spinning
English 'wool' and Latin 'lāna' (which gives us 'lanolin') are cognates from the same PIE root — they just look completely different because the initial *w- was preserved in Germanic but lost in Latin, and the internal consonants shifted differently. The PIE root *h₂wĺ̥h₁neh₂ is one of the key words used to prove that PIE speakers were pastoralists who kept domesticated sheep.