Keel, n.
 1. Shipbuilding A longitudinal timber, or series of timbers scarfed together, extending from stem to stern along the bottom of a vessel. It is the principal timber of the vessel, and, by means of the ribs attached on each side, supports the vessel's frame. In an iron vessel, a combination of plates supplies the place of the keel of a wooden ship. See Illust. of Keelson.
 2. Fig.: The whole ship.
 3. A barge or lighter, used on the Tyne for carrying coal from Newcastle; also, a barge load of coal, twenty-one tons, four cwt. [Eng.]
 4. Bot. The two lowest petals of the corolla of a papilionaceous flower, united and inclosing the stamens and pistil; a carina. See Carina.
 5. Nat. Hist. A projecting ridge along the middle of a flat or curved surface.
 6. Aeronautics In a dirigible, a construction similar in form and use to a ship's keel; in an aëroplane, a fin or fixed surface employed to increase stability and to hold the machine to its course.
 Bilge keel Naut., a keel peculiar to ironclad vessels, extending only a portion of the length of the vessel under the bilges. --Ham. Nav. Encyc.
 False keel. See under False.
 Keel boat. (a) A covered freight boat, with a keel, but no sails, used on Western rivers. [U. S.] (b) A low, flat-bottomed freight boat. See Keel, n., 3.
 Keel piece, one of the timbers or sections of which a keel is composed.
 On even keel, in a level or horizontal position, so that the draught of water at the stern and the bow is the same. --Ham. Nav. Encyc.
 On an even keel a. & adv., steady; balanced; steadily.
 E·ven, a.
 1. Level, smooth, or equal in surface; not rough; free from irregularities; hence uniform in rate of motion of action; as, even ground; an even speed; an even course of conduct.
 2. Equable; not easily ruffled or disturbed; calm; uniformly self-possessed; as, an even temper.
 3. Parallel; on a level; reaching the same limit.
    And shall lay thee even with the ground.   --Luke xix. 44.
 4. Balanced; adjusted; fair; equitable; impartial; just to both sides; owing nothing on either side; -- said of accounts, bargains, or persons indebted; as, our accounts are even; an even bargain.
    To make the even truth in pleasure flow.   --Shak.
 5. Without an irregularity, flaw, or blemish; pure. “I know my life so even.”
 6. Associate; fellow; of the same condition. [Obs.] “His even servant.”
 7. Not odd; capable of division by two without a remainder; -- said of numbers; as, 4 and 10 are even numbers.
    Whether the number of the stars is even or odd.   --Jer. Taylor.
 On even ground, with equal advantage.
 On even keel Naut., in a level or horizontal position.