Prophecies are transmitted through it, but nothing clear-cut (6)

I believe the answer is:

oracle

I'm a little stuck... Click here to teach me more about this clue!

'prophecies are transmitted through it' is the definition.
I can't tell whether this definition defines the answer.

'nothing clear-cut' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'cut' indicates an anagram (cut can mean mixed).
'clear' anagrammed gives 'racle'.
'o'+'racle'='ORACLE'

'but' acts as a link.

Can you help me to learn more?

(Other definitions for oracle that I've seen before include "Diviner of the future" , "Wise words" , "Adviser t" , "Augury" , "She prophesised" .)

I've seen this clue in the Evening Standard.

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