The Collaborative International Dictionary of English v.0.48:
Lap \Lap\ (l[a^]p), n. [OE. lappe, AS. l[ae]ppa; akin to D. lap
patch, piece, G. lappen, OHG. lappa, Dan. lap, Sw. lapp.]
1. The loose part of a coat; the lower part of a garment that
plays loosely; a skirt; an apron. --Chaucer.
2. An edge; a border; a hem, as of cloth. --Chaucer.
If he cuts off but a lap of truth's garment, his
heart smites him. --Fuller.
3. The part of the clothing that lies on the knees or thighs
when one sits down; that part of the person thus covered;
figuratively, a place of rearing and fostering; as, to be
reared in the lap of luxury.
Men expect that happiness should drop into their
4. That part of any substance or fixture which extends over,
or lies upon, or by the side of, a part of another; as,
the lap of a board; also, the measure of such extension
over or upon another thing.
Note: The lap of shingles or slates in roofing is the
distance one course extends over the second course
below, the distance over the course immediately below
being called the cover.
5. (Steam Engine) The amount by which a slide valve at its
half stroke overlaps a port in the seat, being equal to
the distance the valve must move from its mid stroke
position in order to begin to open the port. Used alone,
lap refers to outside lap. See Outside lap (below).
6. The state or condition of being in part extended over or
by the side of something else; or the extent of the
overlapping; as, the second boat got a lap of half its
length on the leader.
7. One circuit around a race track, esp. when the distance is
a small fraction of a mile; as, to run twenty laps; to win
by three laps. See Lap, to fold, 2.
8. In card playing and other games, the points won in excess
of the number necessary to complete a game; -- so called
when they are counted in the score of the following game.
9. (Cotton Manuf.) A sheet, layer, or bat, of cotton fiber
prepared for the carding machine.
10. (Mach.) A piece of brass, lead, or other soft metal, used
to hold a cutting or polishing powder in cutting glass,
gems, and the like, or in polishing cutlery, etc. It is
usually in the form of wheel or disk, which revolves on a
Lap joint, a joint made by one layer, part, or piece,
overlapping another, as in the scarfing of timbers.
Lap weld, a lap joint made by welding together overlapping
edges or ends.
Inside lap (Steam Engine), lap of the valve with respect to
the exhaust port.
Outside lap, lap with respect to the admission, or steam,