boatbuilder vs builder

boatbuilder and builder both are nouns.

Word	Noun	Adjective	Verb	Adverb
boatbuilder	Yes	No	No	No
builder	Yes	No	No	No

As nouns, builder is a hypernym of boatbuilder; that is, builder is a word with a broader meaning than boatbuilder:

boatbuilder: a person who builds boats
builder: someone who contracts for and supervises construction (as of a building)

Other hypernyms of boatbuilder include constructor.

boatbuilder (noun)	builder (noun)
a person who builds boats	someone who contracts for and supervises construction (as of a building)
	a person who creates a business or who organizes and develops a country
	a substance added to soaps or detergents to increase their cleansing action