discipline-n; 4 Senses

Sense Number 1: a field of study, a domain of knowledge

Commentary: DISCIPLINE[+entity][+symbolic][+domain][+knowledge][+science/+medicine/+literature]

The discipline of molecular biology has advanced enormously in recent decades.
Sociology is a fairly new discipline.
He is pursuing the scholarly discipline of Indo-European philology.
Those disciplines are taught only at the graduate level.

WordNet 3.0 Sense Numbers: 1

Sense Number 2: the trail of focused, controlled behavior

Commentary: DISCIPLINE[+quality][+behavior][+controlled][+intentionally]
NOTE: refers to a quality possessed by the subject, not an external system or domain

These modern dancers do not exhibit the discipline of the Russian ballerinas.
The troops showed great discipline on the battlefield.
It took more discipline than Mary had to stick with her austere and boring weight-loss diet.
He was able to maintain discipline among his soldiers. (keep them in that state of behavior)

WordNet 3.0 Sense Numbers: 3

Sense Number 3: training or guidance to improve a skill or ability

Commentary: DISCIPLINE[+activity][+training][+guidance]
NOTE: implies someone or something is providing the training

Many parents would like the public schools to exert more discipline over the students.
The dogs were provided with discipline to learn good off-leash manners.
He quickly experienced the discipline of prison life. (somewhat ironic)
A storm at sea will offer you a lot of discipline in the art of sailing.
They don't give the children much discipline at that daycare center.

WordNet 3.0 Sense Numbers: 2, 4

Sense Number 4: the act of punishment

Commentary: DISCIPLINE[+activity][+punishment]

No form of corporal discipline was allowed at that school. (spanking, slapping, whipping, etc.)
Mary thinks the offenders deserved the harsh discipline they received.
The pranksters received no discipline whatsoever for spraying graffiti on the walls of the school.

WordNet 3.0 Sense Numbers: 5