I turned out to be devoid of proven ability (7)
I believe the answer is:
Here is my best explanation:
'be devoid of proven ability' is the definition.
I can't tell whether this definition defines the answer.
'i turned out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'iturned' with letters rearranged gives 'UNTRIED'.
'to' acts as a link.
Can you help me to learn more?