/uys"bray'keuhr/ , n.
1. Naut. a ship specially built for breaking navigable passages through ice.
2. an opening remark, action, etc., designed to ease tension or relieve formality: A mild joke can be a good icebreaker.
3. a tool or machine for chopping ice into small pieces.
[ 1810-20, Amer.; ICE + BREAKER 1 ]