Rather bleak victory, with lame finish in Test (7)
I believe the answer is:
wintery
'rather bleak' is the definition.
(wintery can mean cold and bleak)
'victory with lame finish in test' is the wordplay.
'victory' becomes 'win' (I've seen this before).
'with' means one lot of letters go next to another.
'finish' says to take the final letters.
'in' means one lot of letters goes inside another.
'test' becomes 'try' (synonyms).
The final letter of 'lame' is 'e'.
'e' put into 'try' is 'tery'.
'win'+'tery'='WINTERY'
(Another definition for wintery that I've seen is " Cold".)