gramps vs granddaddy

gramps and granddaddy both are nouns.

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

As nouns, gramps and granddaddy are synonyms defined as:

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

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