The Collaborative International Dictionary of English v.0.48:
Rule \Rule\, n. [OE. reule, riule, OF. riule, reule, F.
r['e]gle, fr. L. regula a ruler, rule, model, fr. regere,
rectum, to lead straight, to direct. See Right, a., and cf.
1. That which is prescribed or laid down as a guide for
conduct or action; a governing direction for a specific
purpose; an authoritative enactment; a regulation; a
prescription; a precept; as, the rules of various
societies; the rules governing a school; a rule of
etiquette or propriety; the rules of cricket.
We profess to have embraced a religion which
contains the most exact rules for the government of
our lives. --Tillotson.
(a) Uniform or established course of things.
'T is against the rule of nature. --Shak.
(b) Systematic method or practice; as, my ule is to rise
at six o'clock.
(c) Ordibary course of procedure; usual way; comon state
or condition of things; as, it is a rule to which
there are many exeptions.
(d) Conduct in general; behavior. [Obs.]
This uncivil rule; she shall know of it. --Shak.
3. The act of ruling; administration of law; government;
empire; authority; control.
Obey them that have the rule over you. --Heb. xiii.
His stern rule the groaning land obeyed. --Pope.
4. (Law) An order regulating the practice of the courts, or
an order made between parties to an action or a suit.
5. (Math.) A determinate method prescribed for performing any
operation and producing a certain result; as, a rule for
extracting the cube root.
6. (Gram.) A general principle concerning the formation or
use of words, or a concise statement thereof; thus, it is
a rule in England, that s or es, added to a noun in the
singular number, forms the plural of that noun; but "man"
forms its plural "men", and is an exception to the rule.
(a) A straight strip of wood, metal, or the like, which
serves as a guide in drawing a straight line; a ruler.
(b) A measuring instrument consisting of a graduated bar
of wood, ivory, metal, or the like, which is usually
marked so as to show inches and fractions of an inch,
and jointed so that it may be folded compactly.
A judicious artist will use his eye, but he will
trust only to his rule. --South.
(a) A thin plate of metal (usually brass) of the same
height as the type, and used for printing lines, as
between columns on the same page, or in tabular work.
(b) A composing rule. See under Conposing.
As a rule, as a general thing; in the main; usually; as, he
behaves well, as a rule.
Board rule, Caliber rule, etc. See under Board,
Rule joint, a knuckle joint having shoulders that abut when
the connected pieces come in line with each other, and
thus permit folding in one direction only.
Rule of the road (Law), any of the various regulations
imposed upon travelers by land or water for their mutual
convenience or safety. In the United States it is a rule
of the road that land travelers passing in opposite
directions shall turn out each to his own right, and
generally that overtaking persons or vehicles shall turn
out to the left; in England the rule for vehicles (but not
for pedestrians) is the opposite of this.
Rule of three (Arith.), that rule which directs, when three
terms are given, how to find a fourth, which shall have
the same ratio to the third term as the second has to the
first; proportion. See Proportion, 5
Rule of thumb, any rude process or operation, like that of
using the thumb as a rule in measuring; hence, judgment
and practical experience as distinguished from scientific