uncle vs granduncle

uncle and granduncle both are nouns.

Word	Noun	Adjective	Verb	Adverb
uncle	Yes	No	No	No
granduncle	Yes	No	No	No

As nouns, granduncle is a hyponym of uncle; that is, granduncle is a word with a more specific, narrower meaning than uncle:

Other hyponyms of uncle include great-uncle.

uncle (noun)	granduncle (noun)
the brother of your father or mother; the husband of your aunt	an uncle of your father or mother
a source of help and advice and encouragement