icebreaker

noun

1. A ship designed to break through ice so that it, or other ships coming behind, can navigate on frozen seas.

   “The steel hulls of ice-breakers are much thicker than those of standard vessels.”

   “My father's Bonneville was cutting its way toward us like an icebreaker moving through my whole state of consciousness.”

   “The Australian Antarctic Division’s chartered icebreaker the Aurora Australis on a previous mission wedged in ice in Commonwealth Bay 10 nautical miles from Mawson’s Hut in Antarctica.”

2. (figuratively)A game, activity, humorous anecdote, etc., designed to ease tension and encourage interaction among individuals in a situation where they do not know each other well.

   “The new college hallmates were awkward with each other at first, but after a game of charades as an icebreaker, they were laughing like old friends.”

   “The key purpose of an icebreaker is to introduce your group members to each other and to introduce your training session topic. A well-planned icebreaker ensures that a training session will start with more involvement and focus.”

3. A lively song and dance routine at the start of a musical.

   “At the moment the curtain went up there had to be a lively ensemble number of principals and chorus singing and dancing, the traditional “icebreaker” that also covered up the noise of late-arriving ticket holders getting to their seats.”