Second day at the Biergarten, just for men (4)
I believe the answer is:
stag
'just for men' is the definition.
(as in a stag do)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for stag that I've seen before include "Male at party?" , "Male-only" , "Horned animal" , "in a rut, perhaps?" , "Excluding women" .)