The function where execution of a C program starts. On exit from the function, or if exit() or _exit() are called, execution of the program ends. The return value of main() is returned to the environment as an exit status.

The correct definition of main() must be compatible with one of the following declarations:

  • int main(int argc, char *argv[]);
  • int main(void);

Anything else (most particularly, void main() and its variants) are incorrect Schildtisms, and to be avoided at all costs.

Also a short name for the mainsail on a sailboat. This sail is set off of the mast and attaches to the boom. It is the only sail on a cat rig.

Main (?), n. [F. main hand, L. manus. See Manual.]


A hand or match at dice.

Prior. Thackeray.


A stake played for at dice.




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


A match at cockfighting.

"My lord would ride twenty miles . . . to see a main fought."



A main-hamper.




© Webster 1913.

Main, n. [AS. maegen strength, power, force; akin to OHG. magan, Icel. megin, and to E. may, v. . See May, v.]


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.


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, ∨ In the main, for the most part; in the greatest part. -- With might and main, ∨ 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.


© Webster 1913.

Main (?), a. [From Main strength, possibly influenced by OF. maine, magne, great, L. magnus. Cf. Magnate.]


Very or extremely strong.


That current with main fury ran. Daniel.


Vast; huge.

[Obs.] "The main abyss."



Unqualified; absolute; entire; sheer.

[Obs.] "It's a man untruth." Sir W. Scott.


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

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


Important; necessary.


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.


© Webster 1913.

Main, adv. [See Main, a.]

Very extremely; as, main heavy.

"I'm main dry." Foote. [Obs. or Low]


© Webster 1913.

Log in or register to write something here or to contact authors.