a. [f. next or SUBSTRATUM + -AL.] Underlying; fundamental.
1851. Jrnl. R. Agric. Soc., XII. II. 495. This is the substratal view of the origin and relations of the surface soil.
1881. Blackie, Lay Serm., iii. 115. The one proof or evidence that belongs to both is the reasonable substratal element which they imply.
