berg vs iceberg

berg and iceberg both are nouns.

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

As nouns, berg and iceberg are synonyms defined as:

berg and iceberg: a large mass of ice floating at sea; usually broken off of a polar glacier

berg (noun)	iceberg (noun)
a large mass of ice floating at sea; usually broken off of a polar glacier	lettuce with crisp tightly packed light-green leaves in a firm head
	a large mass of ice floating at sea; usually broken off of a polar glacier