- a principal pipe in a system that distributes water or gas or electricity or that collects sewage

- any very large body of (salt) water

1. A hand or match at dice. Prior. Thackeray.

2. A stake played for at dice. [Obs.] Shak.

3. The largest throw in a match at dice; a throw at dice within given limits, as in the game of hazard.

4. A match at cockfighting. "My lord would ride twenty miles . . . to see a main fought." Thackeray.

5. A main-hamper. [Obs.] Ainsworth.

1. Strength; force; might; violent effort. [Obs., except in certain phrases.]

"There were in this battle of most might and main." -- R. of Gl.

"He 'gan advance, With huge force, and with importable main." -- Spenser.

2. The chief or principal part; the main or most important thing. [Obs., except in special uses.]

"Resolved to rest upon the title of Lancaster as the main, and to use the other two . . . but as supporters." -- Bacon.

3. Specifically: (a) The great sea, as distinguished from an arm, bay, etc. ; the high sea; the ocean. "Struggling in the main." Dryden. (b) The continent, as distinguished from an island; the mainland. "Invaded the main of Spain." Bacon. (c) principal duct or pipe, as distinguished from lesser ones; esp. (Engin.), a principal pipe leading to or from a reservoir; as, a fire main.

Forcing main
the delivery pipe of a pump.

For the main
or In the main
for the most part; in the greatest part.

With might and main
or With all one's might and main
with all one's strength; with violent effort.

"With might and main they chased the murderous fox." -- Dryden.

1. Very or extremely strong. [Obs.]

"That current with main fury ran." -- Daniel.

2. Vast; huge. [Obs.] "The main abyss." Milton.

3. Unqualified; absolute; entire; sheer. [Obs.] "It's a man untruth." Sir W. Scott.

4. Principal; chief; first in size, rank, importance, etc.

"Our main interest is to be happy as we can." -- Tillotson.

5. Important; necessary. [Obs.]

"That which thou aright Believest so main to our success, I bring." -- Milton.

By main force
by mere force or sheer force; by violent effort; as, to subdue insurrection by main force.

"That Maine which by main force Warwick did win." -- Shak.

By main strength
by sheer strength; as, to lift a heavy weight by main strength.

Main beam
(Steam Engine), working beam.

Main boom
(Naut.), the boom which extends the foot of the mainsail in a fore and aft vessel.

Main brace
(a) (Mech.) The brace which resists the chief strain. Cf. Counter brace. (b) (Naut.) The brace attached to the main yard.

Main center
(Steam Engine), a shaft upon which a working beam or side lever swings.

Main chance
See under Chance.

Main couple
(Arch.), the principal truss in a roof.

Main deck
(Naut.), the deck next below the spar deck; the principal deck.

Main keel
(Naut.), the principal or true keel of a vessel, as distinguished from the false keel.

Syn. -- Principal; chief; leading; cardinal; capital.

1. Very; extremely; as, main heavy. "I'm main dry." Foote. [Obs. or Low]