basal (adj.)

"bottom of anything considered as its support, foundation, pedestal," early 14c., from Old French bas "depth" (12c.), from Latin basis "foundation," from Greek basis "a stepping, a step, that on which one steps or stands, pedestal," from bainein "to go, walk, step" (from PIE root *gwa- "to go, come").

The military sense of "secure ground from which operations proceed" is attested from 1860. The chemical sense of "compound substance which unites with an acid to form a salt" (1810) was introduced in French 1754 by French chemist Guillaume-François Rouelle (1703-1770).

The sporting sense of "starting point" is from 1690s, also "destination of a runner" (1812). As a "safe" spot in a tag-like or ball game, it is suggested from mid-15c. (as the name of the game later called prisoner's base). Hence baseball, base-runner (1867), base-hit (1874), etc. The meaning "resources on which something draws for operation" (as in power-base, database, etc.) is by 1959.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).