Old 1 and silent 1 each losing a million (3-4)
I believe the answer is:
one-time
'old' is the definition.
(I know that old can be written as one-time)
'1 and silent 1 each losing a million' is the wordplay.
I cannot really understand how this works, but
'1' could be 'one' (synonyms) and 'one' is found within the answer.
'million' could be 'm' (abbreviation) and 'm' is present in the answer.
The remaining letters 'tie' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for one-time that I've seen before include "Relating to a single occasion" , "Former" .)