stratum

Definition

One of several parallel horizontal layers of material arranged one on top of another.

Etymology

Borrowed from Latin strātum (“a spread for a bed, coverlet, quilt, blanket; a pillow, bolster; a bed”), neuter singular of strātus, perfect passive participle of sternō (“spread”). Doublet of estrade.

Example Sentences

• "It is built of alternate strata of brick and clay, and the sides correspond to the direction of the meridians and parallels."
• "He describes the operation thus: "The heavy ram employed to impart the finishing strokes, hoisted up with double purchase and snail's pace to the summit of the Piling Engine, and then falling down like a thunderbolt on the head of the devoted timber, driving it perhaps a single half inch in to the stratum below, is well calculated to put to the test the virtue of patience, while it illustrates the old adage of—slow and sure.""
• "An illuminating article in a recent issue of the Eastern Region's Civil Engineering News points out that where coal is worked over a reasonably large area, it is not only the whole of the strata above the workings, but also an area beyond which is liable to subside at varying rates after the coal has been removed."

Related Words