əˈpīˌrän, -pā- noun
( plural apei·ra -_rə, -ˌrä)
Etymology: Greek, from neuter of apeiros endless, infinite, from a- a- (II) + -peiron (from peirat-, peirar end, conclusion); akin to peri around — more at far
: the unlimited, indeterminate, and indefinite ground, origin, or primal principle of all matter postulated especially by Anaximander