n. [ Scot. See Manse. ] The farm attached to a mansion house; a manse. [ Scot. or Brit. dial. ] [ 1913 Webster ]

n. (Electricity) The source of electrical power in a building; the wiring system of a building. [ PJC ]

n. (Naut.) The principal sail in a ship or other vessel. [ 1913 Webster ]

[ They ] hoised up the mainsail to the wind. Acts xxvii. 40. [ 1913 Webster ]

☞ The mainsail of a ship is extended upon a yard attached to the mainmast, and that of a sloop or schooner upon the boom. [ 1913 Webster ]

n. (Naut.) One of the ropes by which the mainsail is hauled aft and trimmed. [ 1913 Webster ]

n. The principal or most important spring in a piece of mechanism, especially the moving spring of a watch or clock or the spring in a gunlock which impels the hammer. Hence: (Fig.) The chief or most powerful motive; the efficient cause of action; as, the mainspring of action. [ 1913 Webster ]

n. 1. (Naut.) The stay extending from the foot of the foremast to the maintop. [ 1913 Webster ]

2. Main support; principal dependence. [ 1913 Webster ]

The great mainstay of the Church. Buckle. [ 1913 Webster ]

v. t. (Education) TO place (a student) in regular school classes; -- used especially of mentally or physically handicapped children. [ WordNet 1.5 ]

n. The prevailing opinion or practise; as, the doctor avoided using therapies outside the mainstream of modern medical practice. [ PJC ]

adj. (Education) Placed in regular school classes; -- of the handicapped. [ WordNet 1.5 ]

v. i. [ AS. mānswerian to forswear; mān sin, crime + swerian to swear. ] To swear falsely. [ Obs. ] Blount. [ 1913 Webster ]