Brunette
mid 16th century: from French, feminine of brunet, diminutive of brun ‘brown’.
wiktionary
Borrowed from French brunette, the feminine form of brunet, from brun(“brown”). Doublet of burnet.
etymonline
brunette (adj.)
of a woman, "dark in complexion, having a brownish tone to the skin and hair," 1660s, from French brunette, fem. of brunet, from Old French brunet "brownish, brown-haired, dark-complexioned," fem. diminutive of brun "brown" (12c.), of West Germanic origin, from Proto-Germanic *brunaz (from PIE root *bher- (2) "bright; brown").
As a noun, "woman with dark hair and eyes and of a dark complexion," from 1710. The metathesized form, Old French burnete, is the source of the surname Burnett. Burnete also was used of a wool-dyed cloth of superior quality, originally dark brown.
