with might and main
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.
Might, n. Force or power of any kind, whether of body or mind; energy or intensity of purpose, feeling, or action; means or resources to effect an object; strength; force; power; ability; capacity.
What so strong,
But wanting rest, will also want of might? --Spenser.
Thou shalt love the Lord thy God with all thine heart, and with all thy soul, and with all thy might. --Deut. vi. 5.
With might and main. See under 2d Main.