Green’s Dictionary of Slang

(US prison) a white woman; a female member of a white gang.

2013		Nat. Post (Toronto) 6 Apr. 17/5: Female members [...] were called ‘featherwoods.’ They functioned as communication hubs, facilitating gang communication.
2019		D. Winslow Border [ebook] [T]hey thought a Latina should have the job, not a featherwood.
2021		T. Pluck Boy from County Hell 104: They [...] branded the Tyr rune of the Brotherhood on his left tit just like the featherwoods.