geriatrics vs gerontology

geriatrics and gerontology both are nouns.

Word	Noun	Adjective	Verb	Adverb
geriatrics	Yes	No	No	No
gerontology	Yes	No	No	No

As nouns, geriatrics and gerontology are synonyms defined as:

geriatrics and gerontology: the branch of medical science that deals with diseases and problems specific to old people

geriatrics (noun)	gerontology (noun)
the branch of medical science that deals with diseases and problems specific to old people	the branch of medical science that deals with diseases and problems specific to old people