celeriac vs root celery

celeriac and root celery both are nouns.

Word	Noun	Adjective	Verb	Adverb
celeriac	Yes	No	No	No
root celery	Yes	No	No	No

As nouns, celeriac and root celery are synonyms defined as:

Other synonyms of celeriac include Apium graveolens rapaceum, celery root, knob celery, turnip-rooted celery.

celeriac (noun)	root celery (noun)
thickened edible aromatic root of a variety of celery plant	grown for its thickened edible aromatic root
grown for its thickened edible aromatic root