goofball vs fathead

goofball and fathead both are nouns.

Word	Noun	Adjective	Verb	Adverb
goofball	Yes	No	No	No
fathead	Yes	No	No	No

As nouns, goofball and fathead are synonyms defined as:

Other synonyms of goofball include bozo, cuckoo, goof, goose, jackass, twat, zany.

goofball (noun)	fathead (noun)
a man who is a stupid incompetent fool	a man who is a stupid incompetent fool
a person who amuses others by ridiculous behavior