Catch in the light (3)
I believe the answer is:
ray
'light' is the definition.
(ray is a kind of light)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for ray that I've seen before include "Shaft, beam" , "Man who engaged in surrealist photography" , "Gleam" , "Man, maybe" , "Lindwall" .)