Lose a job and prepare to send out messages in December? (3,4,5)
I believe the answer is:
get ones cards
'lose a job' is the definition.
'and prepare to send out messages in december?' is the wordplay.
I cannot really understand how this works, but
'and' could be 'n' (common abbreviation for 'and') and 'n' is found in the answer.
'to' is found in the answer.
'messages' could be 'cards' (card is a kind of message) and 'cards' is found within the answer.
The remaining letters 'gees' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
(Another definition for get ones cards that I've seen is " Be dismissed from one's employment".)