Question

Define the term : Ray​

Answer 1

a ray :

each of the lines in which light (and heat) may seem to stream from the sun or any luminous body, or pass through a small opening.

Answer 2

Any of the lines or streams in which light appears to radiate from a luminous body. The straight line normal to the wave fronts in propagation of radiant energy. A stream of material particle all moving in the same straight lines.