Lover lost a million in test (4)
I believe the answer is:
exam
'test' is the definition.
(synonyms)
'lover lost a million' is the wordplay.
I cannot quite see how this works, but
'a' is within the answer.
'million' could be 'm' (abbreviation) and 'm' is located in the answer.
The remaining letters 'ex' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for exam that I've seen before include "Test (abbr)" , "paper" , "Written test" , "Important test" , "Formal knowledge test" .)