wee: English has two words wee. The older, ‘small’ [OE], was originally a noun, Old English wēg or wēge. This meant ‘weight’, and is closely related to English weigh. Its use in contexts such as a little wee, literally ‘a(chǎn) small weight’, meant that by the 13th century it had shifted semantically to ‘small amount’, but it did not become an adjective until the 15th century. Weeny was derived from it in the 18th century. Wee ‘urine, urinate’ [20] and its reduplication wee-wee [20] are nursery words, and no doubt originated in some sort of fanciful imitation of the sound of urinating. => weigh
wee (adj.)
"extremely small," mid-15c., from earlier noun use in sense of "quantity, amount" (such as a littel wei "a little thing or amount," c. 1300), from Old English w?ge "weight" (see weigh). Adjectival use wee bit apparently developed as parallel to such forms as a bit thing "a little thing." Wee hours is attested by 1891, from Scottish phrase wee sma' hours (1819). Wee folk "faeries" is recorded from 1819. Weeny "tiny, small" is from 1790.