extracurricular

Short definition from Wiktionary

Adjective

1. 1
   Outside of the normal curriculum of an educational establishment.
2. 2
   Similarly outside of the normal duties of a job or profession.
3. 3
   Extramarital.

Noun

1. 1
   An activity outside the normal academic curriculum.
2. 2
   An activity beyond official duties of a job or profession.
3. 3
   An extramarital affair.