Origin and history of basic

c. 1300, "foundation" (of a building, etc.); "pedestal" (of a statue), in general, "bottom of anything considered as its support," 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). Earlier in alchemy it was "an alloy of base metals" (late 15c.).

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, data-base, etc.) is by 1959.

"in essential respects, fundamentally," 1903; see basic (adj.) + -ly (2).