discipline
n. C / Un. the ability to control your behavior and work hard, even when you don't want to. It can also mean the practice of training people to follow strict rules.
n. the practice of training individuals to obey rules or a code of behaviour, often using corrective measures for disobedience. It also refers to the self-control resulting from such training, or a specific branch of academic study.
It takes a lot of discipline to exercise every morning.
The teacher struggled to maintain discipline in the classroom because the students kept talking over her.
While martial arts require immense physical strength, the true focus of the practice is cultivating the mental discipline needed to remain calm under pressure.
From Middle English [Term?], from Anglo-Norman, from Old French descipline, from Latin disciplina (“instruction”), from discipulus (“pupil”), influenced by disco (“to learn”), from Proto-Indo-European *dek- (“(cause to) accept”).
Uncountable when referring to self-control or behavioural training; countable when denoting a specific branch of knowledge.