effective, firm, good, rigorous
We need better discipline in our schools.

harsh, iron, rigid, strict
strict military discipline

lax, poor
Discipline was too lax.

student, team
church, military, party, prison, school, social, work
parental

enforce, exercise, impose
the discipline that the party exercises over its members

instil/instill
We need someone who is good at instilling discipline.

maintain
The teacher was unable to maintain discipline.

submit to
They submitted to the discipline imposed by their leaders.

learn
Students have to learn discipline.

have
The school was criticized for having very poor discipline.

lack
Modern schools lack discipline.

need
She believes children need discipline.

restore

problem

a breach of discipline (esp. BrE)
It's unfair to dismiss somebody for a single breach of discipline.

a breakdown in discipline, a breakdown of discipline
a breakdown of discipline in the classroom

a lack of discipline
order and discipline
He quickly brought order and discipline to the regiment.

good, great
It is good discipline to learn to delegate.

strict
personal
mental, spiritual
physical
business, commercial, financial, fiscal, industrial, market, monetary
The government has stabilized the economy through strict fiscal discipline.

message (= the practice of only talking about what is relevant to your aims, by a politician)

have
He'll never get anywhere working for himself—he has no discipline.

show
lack
apply, bring
something to help you bring discipline to your decision-making process

demand, require, take
It takes great discipline to learn a musical instrument.

a lack of discipline

core, main, major
Students are to be tested on the three core disciplines: mathematics, English and science.

different, distinct, independent, individual, separate
When did sociology emerge as a distinct discipline?

established, traditional
emerging, new
related
social work and its related disciplines

academic, intellectual, scholarly
They established psychology as an academic discipline.

professional (esp. AmE)
humanities, science, scientific, etc.

across disciplines
There is a lack of communication across disciplines (= between teachers and students of different subjects).

within a/the discipline
Within a discipline there may be more than one school of thought.

different disciplines, diverse disciplines
academics from diverse academic disciplines

multiple disciplines (esp. AmE)
experts in multiple disciplines

a range of disciplines
The university offers a wide range of disciplines.