stria (pl. striae).
1. Flat facet in lieu of a flute on a column-shaft. See stopped flute.

2. Fillet between flutes of a Classical column.

3. Rib in Gothic vaults.

4. Any small channel, flute, or indentation in a series, separated by fillets, etc.

stri·a / ˈstrīə/ • n. (pl. stri·ae / ˈstrī-ē/ ) technical a linear mark, slight ridge, or groove on a surface, often one of a number of similar parallel features. ∎  Anat. any of a number of longitudinal collections of nerve fibers in the brain.

stria (archit.) fillet between flutes of columns, etc. XVI; small groove, narrow stripe XVII. — L. stria furrow, grooving.
Hence striate (-ATE2), -ated (-ED1) XVII.

stria (stry-ă) n. (pl. striae) (in anatomy) a streak, line, or thin band. striae gravidarum stretch marks: the lines that appear on the skin of the abdomen of pregnant women, due to excessive stretching of the elastic fibres. Red or purple during pregnancy, they become white after delivery.