—adj. 1. simple; consisting of or characterized by a single element.
2. pertaining to or noting a telecommunications system permitting communication in only one direction at a time.
—n. 1. Math.a basic geometric element in a Euclidean space, being a line segment in one dimension, a triangle in two dimensions, a tetrahedron in three dimensions, and so on: used in topology and linear programming.
2. an apartment having all the rooms on one floor.