disciplined
v. B2 Upper Intermediate US //ˈdɪsəpɫənd// UK //dˈɪsɪplˌɪnd// dis·ci·plined
v. having self-control and the ability to follow a plan or rules. You use this to describe someone who stays focused and does not give in to bad habits.
v. characterized by self-control, orderliness, and adherence to rules or a code of conduct. Often implies the result of training or strict upbringing.
She is a very disciplined student.
The disciplined athlete followed his training schedule without missing a single session.
His disciplined approach to writing allowed him to complete the novel in just six months.