[ap.po.si.tion] n (15c) 1 a: a grammatical construction in which two usu. adjacent nouns having the same referent stand in the same syntactical relation to the rest of a sentence (as the poet and Burns in "a biography of the poet Burns") b: the relation of one of such a pair of nouns or noun equivalents to the other
2. a: an act or instance of apposing; specif: the deposition of successive layers upon those already present (as in cell walls) b: the state of being apposed -- ap.po.si.tion.al adj