Month at work for army swimmer? (7)
I believe the answer is:
octopus
'army swimmer?' is the definition.
(I've seen this before)
'month at work' is the wordplay.
'month' becomes 'oct' (abbreviation for October).
'at' says to put letters next to each other.
'work' becomes 'opus' (I've seen this before).
'oct'+'opus'='OCTOPUS'
'for' acts as a link.
(Other definitions for octopus that I've seen before include "Ocean-dweller" , "Marine creature" , "fairground ride" , "From influential organisation" , "Tentacled marine mollusc" .)