Male animal phase when tail drops off (4)
I believe the answer is:
stag
'male animal' is the definition.
(I've seen this before)
'phase when tail drops off' is the wordplay.
I cannot really understand how this works, but
'tail' could be 'tag' (synonyms) and 'tag' is present in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for stag that I've seen before include "Share speculator" , "This party is for men only" , "Adult male deer, often with antlers" , "Adult male red deer" , "Without women" .)