Beams — fish (4)
I believe the answer is:
rays
<span class="explanation-format__ClueExplanation">This clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">beams</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(rays of light)</span><br/ ><br/ >'<span class="explanation-format__original">fish</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ ></span>
(Other definitions for rays that I've seen before include "we hope to catch occasionally out of the blue?" , "Straight lines extending from a point" , "Sunbeams" , "Narrow beams of light" , "Beams from sun or moon" .)