Green’s Dictionary of Slang

bate n.1

[abbr. SE masturbate + ? SE bait]

(US) an act of masturbation, performed in private but filmed by a webcam.

[US]Salon.com 21 Oct. 🌐 Sometimes all they get is a quick bra flash; other times they get a full-on “bate” (when a girl masturbates on camera).