cotton wool /ˈkɒtən wʊl/noun 2cotton-wool verb 1forms 4 noun2 •(US) Raw fibers of cotton before being processed. •(UK) Soft, absorbent cotton for medical or cosmetic use, protective padding, etc. cotton-wool verb1 •To cover with, or in, cotton wool. formscotton-wooled · cotton-wooling · cotton-wools · cotton wools