Elective
A subject you choose, as opposed to the compulsory language.
CBSE Class 11 needs one compulsory language plus four electives for a total of five main subjects, with an optional sixth. Electives include academic subjects such as Physics or History, additional languages, and skill subjects.
The word is also used for the "Elective" versions of languages, such as English Elective (001) and Hindi Elective (002), which go deeper into literature than the Core versions.