What is the meaning of Stria?

A minute groove, or channel; a threadlike line, as of color; a narrow structural band or line; a striation; as, the striae, or groovings, produced on a rock by a glacier passing over it; the striae on the surface of a shell; a stria of nervous matter in the brain.

Source: Webster’s Revised Unabridged Dictionary (1913), via OPTED