molester vs offender

molester and offender both are nouns.

Word	Noun	Adjective	Verb	Adverb
molester	Yes	No	No	No
offender	Yes	No	No	No

As nouns, offender is a hypernym of molester; that is, offender is a word with a broader meaning than molester:

molester: someone who subjects others to unwanted or improper sexual activities
offender: a person who transgresses moral or civil law

Other hypernyms of molester include wrongdoer.

molester (noun)	offender (noun)
someone who subjects others to unwanted or improper sexual activities	a person who transgresses moral or civil law