regulation
n. C / Un. an official rule or law that controls how something is done. You usually see these in business, sports, or government to keep things safe and fair.
n. an official rule, law, or order prescribed by an authority to manage conduct or systems. Often used to describe the act of controlling an activity through such rules.
The new safety regulation requires everyone to wear a helmet.
The government introduced a strict regulation to limit the amount of plastic waste that factories can produce each year.
While the industry initially resisted government oversight, the new regulation eventually provided a stable framework that encouraged long-term investment by reducing legal uncertainty.
From regulate + -ion.
Countable when referring to a specific rule; uncountable when referring to the general process of controlling an activity. Often used as an attributive noun, as in 'regulation size' or 'regulation uniform'.