base n.

"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.

late 14c., "low, of little height," from Old French bas "low, lowly, mean," from Late Latin bassus "thick, stumpy, low" (used only as a cognomen in classical Latin, humilis being there the usual word for "low in stature or position"), which is of uncertain origin, possibly from Oscan, or Celtic, or related to Greek basson, comparative of bathys "deep."

The meaning "low on the social scale" is from late 15c.; that of "low in the moral scale" is attested by 1530s in English. The meaning "befitting an inferior person or thing, unworthy" is from 1590s. Base metals (c. 1600) were worthless in contrast to noble or precious metals. Related: Basely.

1580s, transitive, "make or serve as a foundation for;" by 1841, of arguments, etc., "place (on or upon) a foundation," from base (n.). Related: Based; basing.