hollow and curved like the inside of a bowl; concave.

of inferior quality, status, rank, etc.

a hole (in the ground).

a deep place.

the act of bending something or oneself (in reverence or submission).

(phys.) the spreading of a wave motion, as light, as it passes an obstacle and expands into the region that is behind the obstacle and hence not directly exposed to the incoming waves; diffraction.

the shape, outline or configuration of anything; structure as apart from colour, material, etc.; a form.

a thing serving as a model of something to be done, drawn, painted, etc.

in a straight direction; unswervingly.