Synonyms of the word

extramarital

• adj. Taking place outside marriage.
• adj. Adulterous.

adulterous

• adj. Of, or characterized by adultery.

extracurricular

• adj. Outside of the normal curriculum of an educational establishment.
• adj. Similarly outside of the normal duties of a job or profession.
• adj. (informal) extramarital.
• n. (education) An activity outside the normal academic curriculum.
• n. (informal) An activity beyond official duties of a job or profession.
• n. (informal) An extramarital affair.

illicit

• adj. (law) Not approved by law, but not invalid.
• adj. Breaking social norms.
• adj. Unlawful.