\Keel\ (k[=e]l), v. t. & i. [AS. c[=e]lan to cool, fr.
c[=o]l cool. See {Cool}.]
To cool; to skim or stir. [Obs.]
      While greasy Joan doth keel the pot.     --Shak.

\Keel\, n.
A brewer's cooling vat; a keelfat.

\Keel\, n. [Cf. AS. ce['o]l ship; akin to D. & G. kiel
keel, OHG. chiol ship, Icel. kj[=o]ll, and perh. to Gr.
gay^los a round-built Ph[oe]nician merchant vessel, gaylo`s
bucket; cf. Skr. g[=o]la ball, round water vessel. But the
meaning of the English word seems to come from Icel. kj["o]lr
keel, akin to Sw. k["o]l, Dan. kj["o]l.]
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 Type 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.
{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.

\Keel\, v. i. [imp. & p. p. {Keeled}; p. pr. & vb. n.
{Keeling}.]
1. To traverse with a keel; to navigate.
2. To turn up the keel; to show the bottom.
{To keel over}, to upset; to capsize. [Colloq.]

\Keel\, n. (A["e]ronautics)
In a dirigible, a construction similar in form and use to a
ship's keel; in an a["e]roplane, a fin or fixed surface
employed to increase stability and to hold the machine to its
course.