sexual assault vs sex offense

sexual assault and sex offense both are nouns.

Word	Noun	Adjective	Verb	Adverb
sexual assault	Yes	No	No	No
sex offense	Yes	No	No	No

As nouns, sexual assault and sex offense are synonyms defined as:

sexual assault and sex offense: a statutory offense that provides that it is a crime to knowingly cause another person to engage in an unwanted sexual act by force or threat

Other synonyms of sexual assault include sex crime, sexual abuse.

sexual assault (noun)	sex offense (noun)
a statutory offense that provides that it is a crime to knowingly cause another person to engage in an unwanted sexual act by force or threat	a statutory offense that provides that it is a crime to knowingly cause another person to engage in an unwanted sexual act by force or threat