Whip-round? It may be implied (5)
I believe the answer is:
tacit
'be implied' is the definition.
(synonyms)
'whip-round? it' is the wordplay.
'whip' becomes 'cat' (cat o' nine tails, cat for short is a type of whip).
'round?' says the letters should be written in reverse (I've seen 'round' mean this).
'cat' reversed gives 'tac'.
'tac'+'it'='TACIT'
'may' is the link.
(Other definitions for tacit that I've seen before include "Understood without being directly expressed" , "Unrecorded" , "Implied but not directly expressed" , "Understood, implicit" , "Silent but implied" .)