discipline

From Middle English, borrowed via Anglo-Norman from Old French descipline, itself from Latin disciplina, meaning 'instruction.' That Latin word traces to discipulus, 'pupil,' shaped along the way by disco, 'to learn,' and ultimately the Proto-Indo-European root *dek-, 'to accept.'

The word began as a term for teaching or instruction, tied closely to the pupil who received it, before its emphasis shifted toward the training and self-control that such instruction was meant to produce.

It shares roots with words built on the idea of learning and accepting — its Latin ancestor disciplina grew out of discipulus, 'pupil,' and disco, 'to learn,' the same root sense that ties it to the very idea of a student.