n. 1 flat surface such that a straight linejoining any two points on it lies wholly in it. 2 level surface. 3 colloq. = AEROPLANE. 4 flat surface producing lift by the action of air or water over and under it (usu. in comb.: hydroplane). 5 (often foll. by of) level of attainment, knowledge, etc.adj. 1 (of a surface etc.) perfectly level. 2 (of an angle, figure, etc.) lying in a plane. v. (ning) glide. [Latin planus PLAIN]
