granddaddy vs gramps

granddaddy and gramps both are nouns.

Word	Noun	Adjective	Verb	Adverb
granddaddy	Yes	No	No	No
gramps	Yes	No	No	No

As nouns, granddaddy and gramps are synonyms defined as:

Other synonyms of granddaddy include grandad, granddad, grandfather, grandpa.

granddaddy (noun)	gramps (noun)
the father of your father or mother	the father of your father or mother