stern vs stark

stern is a noun but stark is not a noun.

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

As adjectives, stern and stark are synonyms defined as:

Other synonyms of stern include austere, severe.

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

stern (adjective)	stark (adjective)
severe and unremitting in making demands	complete or extreme
not to be placated or appeased or moved by entreaty	providing no shelter or sustenance
of a stern or strict bearing or demeanor; forbidding in aspect	severely simple
severely simple	devoid of any qualifications or disguise or adornment
	without qualification; used informally as (often pejorative) intensifiers

stern (adverb)	stark (adverb)
	to the fullest degree