Not following rules or not having control over one's behavior; wild or unruly.
From Latin 'disciplina' (teaching, training), with the prefix 'un-' negating it. Someone without discipline lacks the training or self-control to stay organized.
The word 'discipline' comes from the same root as 'disciple'—both mean a student or follower, implying someone who has been trained and learned to follow a path.
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