recidivist vs backslider

recidivist and backslider both are nouns.

Word	Noun	Adjective	Verb	Adverb
recidivist	Yes	No	No	No
backslider	Yes	No	No	No

As nouns, recidivist and backslider are synonyms defined as:

recidivist and backslider: someone who lapses into previous undesirable patterns of behavior

Other synonyms of recidivist include reversionist.

recidivist (noun)	backslider (noun)
someone who lapses into previous undesirable patterns of behavior	someone who lapses into previous undesirable patterns of behavior
someone who is repeatedly arrested for criminal behavior (especially for the same criminal behavior)