'lee' (shelter) originates from Old English, specifically the word 'hlēo' (or 'hlēow'), where the root meant 'shelter' or 'cover'. The sense 'lees' (dregs) comes from Old French, specifically 'lie' (plural 'lies'), meaning 'sediment'.

'lee' changed from Old English 'hlēo' into Middle English 'lee' and eventually became the modern English word 'lee'. The 'dregs' sense entered English via Old French 'lie(s)', becoming the English plural form 'lees'.

Initially, the shelter sense meant 'shelter or protection from the elements' and this meaning has largely remained. The dregs sense originally meant 'sediment or deposit (of wine)' and remains specialized as 'the lees' in modern usage.