n. The foundation of anything; that on which a thing stands or on which anything is reared; a foundation, groundwork, or supporting principle: now most commonly used of immaterial things.n. In architecture, same as base, 3.n. A pedestal.n. The principal constituent of a compound; a fundamental ingredient.n. Milit., same as base, 15n. . In crystallography and petrography, same as basal plane (which see, under basal).n. In botany and conchology, same as base, 4.n. [NL.] In anatomy, the base; the fundamental or basilar part of anything: as, basis cranii, the base of the skull.n. In prosody, a trochee or its substitute preceding the dactyls of a logaœdic series.n. Same as basipodite.