noun

1. physical strength; force; power: now only in with might and main, with all one's strength

2. Etymology: < mainthe

   the principal or most important part or point: usually in the phrase in the main, mostly, chiefly
3. a principal pipe, conduit, or line in a distribution system for water, gas, electricity, etc.
4. Old Poet. the high, or open, sea; ocean
5. Archaic the mainland
6. Obsolete any broad expanse
7. Naut.
   1. mainmast
   2. mainsail

Etymology: ME < OE mægen, akin to ON magn: see might

adjective

1. Obsolete strong; powerful
2. chief in size, extent, importance, etc.; principal; leading; specif., designating a large central unit on which subsidiaries or branches depend the main post office
3. of, near, or connected with the mainmast or mainsail
4. Brit., Dialectal remarkable; considerable
5. Obsolete designating a broad expanse of land, sea, or space

Etymology: ME mayn < OE mægen- (in comp.) & ON meginn, strong

Etymology: G < Gaul Moenus < IE *moin-, river name < base *mei-, to go, wander > L meare, to go