1. Show displeasure, as after a performance or speech
   - hiss

1. A cry or noise made to express displeasure or contempt
   - hoot, Bronx cheer [N. Amer], hiss, raspberry, razzing [N. Amer], razz [N. Amer], snort, bird

1. Expressing disapproval 
2. Exclamation used to startle or frighten

Derived forms: booing, boos, booed

Type of: call, condemn, cry, outcry, shout, vociferation, yell

Antonym: applaud

Encyclopedia: Boo

• out-of-court settlement
• out-of-date
• out-of-door
• out-of-pocket
• out-of-school
• out-of-the-box thinking
• out-of-town
• out-tray
• outage
• Outaouais
• outargue
• outback
• outbalance
• outbid
• outboard
• outboard motor
• outboard motorboat
• outbound
• outbrave
• outbreak
• outbred
• outbuilding
• outburst
• outcall
• outcast