regulation

WordReference Random House Learner's Dictionary of American English © 2026

reg•u•la•tion /ˌrɛgyəˈleɪʃən/   n. 

1. [countable] a law, rule, or other order given by authority, esp. to regulate conduct.
2. the act of regulating or the state of being regulated:
   [uncountable] strict regulation of the number of cars entering the country.

adj. [usually: before a noun]

3. ordered by or agreeing with regulation:
   regulation army equipment.

See -reg-.

WordReference Random House Unabridged Dictionary of American English © 2026

reg•u•la•tion  (reg′yə lā′shən), n. 

1. a law, rule, or other order prescribed by authority, esp. to regulate conduct.
2. the act of regulating or the state of being regulated.
3. Mechanical Engineering [Mach.] the percentage difference in some quantity related to the operation of an apparatus or machine, as the voltage output of a transformer or the speed of a motor, between the value of the quantity at no-load operation and its value at full-load operation.
4. Electronics the difference between maximum and minimum voltage drops between the anode and the cathode of a gas tube for a specified range of values of the anode current.
5. Sport the normal, prescribed duration of a game according to the sport's regulations, exclusive of any extra innings, overtime period, etc.:
   The Knicks tied the score in the final seconds of regulation, sending the game into overtime.

adj. 

6. prescribed by or conforming to regulation:
   regulation army equipment.
7. usual;
   normal;
   customary:
   the regulation decorations for a Halloween party.

• regulate + -ion 1665–75

Synonyms

• 2. direction, management, control, disposition, adjustment.

Collins Concise English Dictionary © HarperCollins Publishers::

regulation / ˌrɛɡjʊˈleɪʃən/ noun

1. the act or process of regulating
2. a rule, principle, or condition that governs procedure or behaviour
3. (modifier) as required by official rules or procedure: regulation uniform
4. (modifier) normal; usual; conforming to accepted standards: a regulation haircut