cob vs swan

cob and swan both are nouns.

Word	Noun	Adjective	Verb	Adverb
cob	Yes	No	No	No
swan	Yes	No	Yes	No

As nouns, swan is a hypernym of cob; that is, swan is a word with a broader meaning than cob:

cob: adult male swan
swan: stately heavy-bodied aquatic bird with very long neck and usually white plumage as adult

cob (noun)	swan (noun)
adult male swan	stately heavy-bodied aquatic bird with very long neck and usually white plumage as adult
stocky short-legged harness horse
white gull having a black back and wings
nut of any of several trees of the genus Corylus

cob (verb)	swan (verb)
	to declare or affirm solemnly and formally as true
	move about aimlessly or without any destination, often in search of food or employment
	sweep majestically