berg vs growler

berg and growler both are nouns.

Word	Noun	Adjective	Verb	Adverb
berg	Yes	No	No	No
growler	Yes	No	No	No

As nouns, growler is a hyponym of berg; that is, growler is a word with a more specific, narrower meaning than berg:

berg: a large mass of ice floating at sea; usually broken off of a polar glacier
growler: a small iceberg or ice floe just large enough to be hazardous for shipping

berg (noun)	growler (noun)
a large mass of ice floating at sea; usually broken off of a polar glacier	a small iceberg or ice floe just large enough to be hazardous for shipping
	a speaker whose voice sounds like a growl