'boo' definitions:

Definition of 'boo'

(from WordNet)
noun
A cry or noise made to express displeasure or contempt [syn: boo, hoot, Bronx cheer, hiss, raspberry, razzing, razz, snort, bird]
verb
Show displeasure, as after a performance or speech [syn: boo, hiss] [ant: acclaim, applaud, clap, spat]

Definition of 'boo'

From: GCIDE
  • Bo \Bo\, interj. [Cf. W. bw, an interj. of threatening or frightening; n., terror, fear, dread.] An exclamation used to startle or frighten. [Spelt also boh and boo.] [1913 Webster]

Definition of 'boo'

From: GCIDE
  • boo \boo\ v. to show displeasure (after a performance or speech) by making a prolonged sound of "boo". [WordNet 1.5]

Synonyms of 'boo'

From: Moby Thesaurus

Words containing 'boo'