(a) Toward the back of the body; (b) with the back turned in the direction of movement or destination; (go) back foremost; (fall, be borne) back undermost; (lie) back; (c) with the back turned toward……

(a) With verbs implying motion: to a lower place, down, downward; also fig.; (b) with verbs implying rest: at a lower place, below, down; also fig.; (c) with verbs of looking, etc.: downward; casten……

(a) Astron. Not at right angle to the horizon, obliquely; (b) her. (divided) diagonally; 'per bend' or 'per bend sinister'. …