stern vs exacting

stern is a noun but exacting is not a noun.

Word	Noun	Adjective	Verb	Adverb
stern	Yes	Yes	No	No
exacting	No	Yes	No	No

As adjectives, stern and exacting are synonyms defined as:

Other synonyms of stern include strict.

stern (noun)	exacting (noun)
the rear part of a ship
the fleshy part of the human body that you sit on

stern (adjective)	exacting (adjective)
severe and unremitting in making demands	having complicated nutritional requirements; especially growing only in special artificial cultures
not to be placated or appeased or moved by entreaty	requiring precise accuracy
of a stern or strict bearing or demeanor; forbidding in aspect	severe and unremitting in making demands
severely simple