unfounded vs groundless

unfounded and groundless both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unfounded	No	Yes	No	No
groundless	No	Yes	No	No

As adjectives, unfounded and groundless are synonyms defined as:

Other synonyms of unfounded include baseless, idle, unwarranted, wild.

unfounded (adjective)	groundless (adjective)
without a basis in reason or fact	without a basis in reason or fact