rotten vs lousy

rotten and lousy both are adjectives.

Word	Noun	Adjective	Verb	Adverb
rotten	No	Yes	No	No
lousy	No	Yes	No	No

As adjectives, rotten and lousy are synonyms defined as:

Other synonyms of rotten include crappy, icky, shitty, stinking, stinky.

rotten (adjective)	lousy (adjective)
having decayed or disintegrated; usually implies foulness	very bad
damaged by decay; hence unsound and useless	infested with lice
very bad	vile; despicable