Lap joint

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. [1913 Webster]

2. An edge; a border; a hem, as of cloth. --Chaucer. [1913 Webster]

If he cuts off but a lap of truth's garment, his heart smites him. --Fuller. [1913 Webster]

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. [1913 Webster]

Men expect that happiness should drop into their laps. --Tillotson. [1913 Webster]

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. [1913 Webster]

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. [1913 Webster]

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). [1913 Webster]

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. [1913 Webster]

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. [1913 Webster]

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. [1913 Webster]

9. (Cotton Manuf.) A sheet, layer, or bat, of cotton fiber prepared for the carding machine. [1913 Webster]

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 vertical axis. [1913 Webster]

{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, port. [1913 Webster]