Restraint is calm, controlled, and unemotional behaviour. They behaved with more restraint than I'd expected. I'll speak to the staff and ask them to exercise restraint and common sense. Restraint of something is the act of preventing it from increasing too much or from being done freely.
a device that restrains, such as a harness:[countable] a child restraint for use in the car. reserve in feelings, behavior, etc.:[uncountable] speaking with restraint.
Definition of restraint noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.
There are 11 meanings listed in OED's entry for the noun restraint, two of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.
1. the ability to control or moderate one's impulses, passions, etc: to show restraint.