having or exhibiting discipline; rigorous: paintings characterized by a disciplined technique.

Is discipline a verb or adjective?

verb (used with object), dis·ci·plined, dis·ci·plin·ing. to train by instruction and exercise; drill. to bring to a state of order and obedience by training and control. to punish or penalize in order to train and control; correct; chastise.

What kind of word is discipline?

discipline used as a noun:

A systematic method of obtaining obedience. A state of order based on submission to authority. A punishment to train or maintain control. A set of rules regulating behaviour.