rule (rūl)
n.

1. 1. Governing power or its possession or use; authority.
   2. The duration of such power.
2. 1. An authoritative, prescribed direction for conduct, especially one of the regulations governing procedure in a legislative body or a regulation observed by the players in a game, sport, or contest.
   2. The body of regulations prescribed by the founder of a religious order for governing the conduct of its members.
3. A usual, customary, or generalized course of action or behavior: "The rule of life in the defense bar ordinarily is to go along and get along" (Scott Turow).
4. A generalized statement that describes what is true in most or all cases: In this office, hard work is the rule, not the exception.
5. Mathematics. A standard method or procedure for solving a class of problems.
6. Law.
   1. A court order limited in application to a specific case.
   2. A subordinate regulation governing a particular matter.
7. See ruler (sense 1).
8. Printing. A thin metal strip of various widths and designs, used to print borders or lines, as between columns.

v., ruled, rul·ing, rules.

v.tr.

1. To exercise control, dominion, or direction over; govern.
2. To dominate by powerful influence.
3. To decide or declare authoritatively or judicially; decree. See synonyms at decide.
4. 1. To mark with straight parallel lines.
   2. To mark (a straight line), as with a ruler.

v.intr.

1. To be in total control or command; exercise supreme authority.
2. To formulate and issue a decree or decision.
3. To prevail at a particular level or rate: Prices ruled low.
4. Slang. To be excellent or superior: That new video game rules!

phrasal verb:

rule out

1. To prevent; preclude: The snowstorm ruled out their weekly meeting.
2. To remove from consideration; exclude: The option of starting over has been ruled out.

idiom:

as a rule

1. In general; for the most part: As a rule, we take the bus.

[Middle English reule, from Old French, from Vulgar Latin *regula, from Latin rēgula, rod, principle.]

rulable rul'a·ble adj.

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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