iceboat vs icebreaker

iceboat and icebreaker both are nouns.

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

As nouns, iceboat and icebreaker are synonyms defined as:

iceboat and icebreaker: a ship with a reinforced bow to break up ice and keep channels open for navigation

iceboat (noun)	icebreaker (noun)
a ship with a reinforced bow to break up ice and keep channels open for navigation	a beginning that relaxes a tense or formal atmosphere
a sailing vessel with runners and a cross-shaped frame; suitable for traveling over ice	a ship with a reinforced bow to break up ice and keep channels open for navigation