rowing boat vs rowboat

rowing boat and rowboat both are nouns.

Word	Noun	Adjective	Verb	Adverb
rowing boat	Yes	No	No	No
rowboat	Yes	No	No	No

As nouns, rowboat is a hypernym of rowing boat; that is, rowboat is a word with a broader meaning than rowing boat:

rowing boat: a rowboat
rowboat: a small boat of shallow draft with cross thwarts for seats and rowlocks for oars with which it is propelled

Other hypernyms of rowing boat include dinghy, dory.

rowing boat (noun)	rowboat (noun)
a rowboat	a small boat of shallow draft with cross thwarts for seats and rowlocks for oars with which it is propelled