icebreaker vs beginning

icebreaker and beginning both are nouns.

Word	Noun	Adjective	Verb	Adverb
icebreaker	Yes	No	No	No
beginning	Yes	Yes	No	No

As nouns, beginning is a hypernym of icebreaker; that is, beginning is a word with a broader meaning than icebreaker:

Other hypernyms of icebreaker include commencement, start.

icebreaker (noun)	beginning (noun)
a beginning that relaxes a tense or formal atmosphere	the act of starting something
a ship with a reinforced bow to break up ice and keep channels open for navigation	the first part or section of something
	the event consisting of the start of something
	the place where something begins, where it springs into being
	the time at which something is supposed to begin

icebreaker (adjective)	beginning (adjective)
	serving to begin