Originally: the woof or weft in a web. Later also: the warp in a web. Frequently attributive, as "abb thread", "abb wool", etc.
((n.) Among weavers, yarn for the warp. Hence, abb wool is wool for
the abb.)
Origin:
Old English; earliest use found in Cleopatra Glossary. Apparently from Old English ō-, prefix + web; compare the parallel formation represented by Old English ōwef.