originally used to describe a sliver of combined wool ready for spinning into worsted yarns. Now also applied to the material produced by cutting or breaking continuous filament tows of man-made fibres.
Top. A wool sliver that has been combed to straighten the fibers and to remove short fiber; an intermediate stage in the production of worsted yarn. ... Top... a continuous untwisted strand of wool fibers of predetermined length from which the short fibers (noils) have been removed in the combing process.