Boo

buh

(loud exclamation intended to scare someone)

buh

(word used ironically in a situation where one might have scared someone, but said someone was not scared)

buh

(exclamation used by a member of an audience)

Buhruf

(derisive shout)

ausbuhen

(to shout boos at (transitive))

buhen

(to shout boos derisively (intransitive))