[1] : The Collaborative International Dictionary of English v.0.48

main \main\ m=an, a. from main strength, possibly
   influenced by of. maine, magne, great, l. magnus. cf.
   magnate.
   1. very or extremely strong. obs.
      1913 webster

            that current with main fury ran.      --daniel.
      1913 webster

   2. vast; huge. obs. "the main abyss." --milton.
      1913 webster

   3. unqualified; absolute; entire; sheer. obs. "it's a man
      untruth." --sir w. scott.
      1913 webster

   4. principal; chief; first in size, rank, importance, etc.;
      as, the main reason to go; the main proponent.
      1913 webster +pjc

            our main interest is to be happy as we can.
                                                  --tillotson.
      1913 webster

   5. important; necessary. obs.
      1913 webster

            that which thou aright
            believest so main to our success, i bring. --milton.
      1913 webster

   by main force, by mere force or sheer force; by violent
      effort; as, to subdue insurrection by main force.
      1913 webster

            that maine which by main force warwick did win.
                                                  --shak.
      1913 webster

   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.
      1913 webster

   syn: principal; chief; leading; cardinal; capital.
        1913 webster
see also:
main magnate by main force by main strength main beam main boom 
main brace counter brace main center main chance chance 
main couple main deck main keel 

[2] : The Collaborative International Dictionary of English v.0.48

main deck \main deck\ n.
   the uppermost sheltered deck that runs the entire length of a
   large vessel.

   syn: second deck.
        wordnet 1.5

[3] : WordNet (r) 2.0

main deck
     n : the uppermost sheltered deck that runs the entire length of
         a large vessel syn: second deck
see also:
second deck 

Deck >> D Words
Deck, definition of term: Deck
deck_pag1.html

Deck Out >> D Words
Deck Out, definition of term: Deck Out
deck+out_pag1.html

Deck Chair >> D Words
Deck Chair, definition of term: Deck Chair
deck+chair_pag1.html

Flight Deck >> F Words
Flight Deck, definition of term: Flight Deck
flight+deck_pag1.html

Dusty Deck >> D Words
Dusty Deck, definition of term: Dusty Deck
dusty+deck_pag1.html

Cassette Deck >> C Words
Cassette Deck, definition of term: Cassette Deck
cassette+deck_pag1.html

Berth Deck >> B Words
Berth Deck, definition of term: Berth Deck
berth+deck_pag1.html