In
weaving cloth, the
warp is the set of lengthwise
yarns that are held in tension on a frame or
loom. The yarn that is inserted over-and-under the warp threads is called the
weft, woof, or filler. Each individual warp thread in a fabric is called a
warp end or
end. Warp means "that which is thrown across" (Old
English wearp, from
weorpan, to throw, cf.
German werfen,
Dutch werpen).