from
The Collaborative International Dictionary of English v.0.48
Flap \Flap\, n. [OE. flappe, flap, blow, bly-flap; cf. D. flap,
and E. flap, v.]
Anything broad and limber that hangs loose, or that is
attached by one side or end and is easily moved; as, the flap
of a garment.
[1913 Webster]
A cartilaginous flap upon the opening of the larynx.
--Sir T.
Browne.
[1913 Webster]
2. A hinged leaf, as of a table or shutter.
[1913 Webster]
3. The motion of anything broad and loose, or a stroke or
sound made with it; as, the flap of a sail or of a wing.
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4. pl. (Far.) A disease in the lips of horses.
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5. (Aeronautics) a movable part of an airplane wing, used to
increase lift or drag, especially when taking off or
landing. used often in the plural.
[WordNet 1.5]
{Flap tile}, a tile with a bent up portion, to turn a corner
or catch a drip.
{Flap valve} (Mech.), a valve which opens and shuts upon one
hinged side; a clack valve.
[1913 Webster]