Definitions
1.AdjectiveOutside of the normal curriculum of an educational establishment."The students enjoy a number of extracurricular activities at weekends."
2.AdjectiveSimilarly outside of the normal duties of a job or profession.
3.AdjectiveExtramarital. (Can we add an example for this sense?)
4.NounAn activity outside the normal academic curriculum.
5.NounAn activity beyond official duties of a job or profession.
6.NounAn extramarital affair.