late 14c., "action of founding," from Old French fondacion "foundation" (14c.) or directly from Late Latin fundationem (nominative fundatio) "a founding," noun of action from past-participle stem of Latin fundare "to lay a bottom or foundation" (see found (v.1)). The Latin word is glossed in Old English by staþol.
Specialized sense of "establishment of an institution with an endowment to pay for it" is from late 14c.; meaning "that which is founded" (a college, hospital, etc.) is from 1510s; meaning "funds endowed for benevolent or charitable purposes" is from early 15c. Sense of "solid base of a structure" is from early 15c. The cosmetics sense of "colored cream applied to the face to make it appear uniform in color and texture" is by 1931, probably short for foundation cream or foundation makeup.
It forms all or part of: alchemy; chyle; chyme; confound; confuse; diffuse; diffusion; effuse; effusion; effusive; fondant; fondue; font (n.2) "complete set of characters of a particular face and size of type;" found (v.2) "to cast metal;" foundry; funnel; fuse (v.) "to melt, make liquid by heat;" fusible; fusion; futile; futility; geyser; gush; gust (n.) "sudden squall of wind;" gut; infuse; ingot; parenchyma; perfuse; perfusion; profuse; refund; refuse (v.) "reject, disregard, avoid;" refuse (n.) "waste material, trash;" suffuse; suffusion; transfuse; transfusion.
It is the hypothetical source of/evidence for its existence is provided by: Greek khein "to pour," khoane "funnel," khymos "juice;" Latin fundere (past participle fusus) "melt, cast, pour out;" Gothic giutan, Old English geotan "to pour;" Old English guttas (plural) "bowels, entrails;" Old Norse geysa "to gush;" German Gosse "gutter, drain."