1. An elongate, thick-walled, tapering plant cell that lacks protoplasm and has a small lumen.

2. A very slender root.

The set of points in the total space of a bundle which are sent into the same element of the base of the bundle by the projection map.

1. The characteristic of wrought metal that indicates directional properties as revealed by etching or by fracture appearance.

2. The pattern of preferred orientation of metal crystals after a deformation process, usually wiredrawing.

A transparent threadlike object made of glass or clear plastic, used to conduct light along selected paths.

An extremely long, pliable, cohesive natural or manufactured threadlike object from which yarns are spun to be woven into textiles.