nubble vs swelling

nubble and swelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
nubble	Yes	No	No	No
swelling	Yes	No	No	No

As nouns, swelling is a hypernym of nubble; that is, swelling is a word with a broader meaning than nubble:

nubble: a small lump or protuberance
swelling: something that bulges out or is protuberant or projects from its surroundings

nubble (noun)	swelling (noun)
a small lump or protuberance	the increase in volume of certain substances when they are heated (often accompanied by release of water)
	something that bulges out or is protuberant or projects from its surroundings
	an abnormal protuberance or localized enlargement