Lost bun initially consumed (6)
I believe the answer is:
beaten
'lost' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I don't see?
'bun initially consumed' is the wordplay.
'initially' says to take the initial letters.
'consumed' becomes 'eaten' (similar in meaning).
The initial letter of 'bun' is 'b'.
'b'+'eaten'='BEATEN'
Can you help me to learn more?
(Other definitions for beaten that I've seen before include "Defeated - whipped" , "Describes a path much trodden" , "Thrashed or whisked" , "Failed to win - punished" , "Hammered" .)