gunnel vs blennioid

gunnel and blennioid both are nouns.

Word	Noun	Adjective	Verb	Adverb
gunnel	Yes	No	No	No
blennioid	Yes	No	No	No

As nouns, blennioid is a hypernym of gunnel; that is, blennioid is a word with a broader meaning than gunnel:

gunnel: small eellike fishes common in shallow waters of the northern Atlantic
blennioid: elongated mostly scaleless marine fishes with large pectoral fins and reduced pelvic fins

Other hypernyms of gunnel include blennioid fish.

gunnel (noun)	blennioid (noun)
small eellike fishes common in shallow waters of the northern Atlantic	elongated mostly scaleless marine fishes with large pectoral fins and reduced pelvic fins
wale at the top of the side of boat; topmost planking of a wooden vessel