Inform about gins (4)
I believe the answer is:
sing
'inform' is the definition.
(I know that sing is a more specific form of tell)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sing that I've seen before include "Act as informer" , "pipe" , "Perform (a song)" , "Celebrate" , "Grass" .)