Nothing to hold down a belief (7)
I believe the answer is:
opinion
'a belief' is the definition.
(I know that belief can be written as opinion)
'nothing to hold down' is the wordplay.
'nothing' becomes 'O' (looks like zero - 0).
'to' is a charade indicator (letters next to each other).
'hold down' becomes 'pinion' (pinioning is a kind of holding. I am not sure about the 'down' bit.).
'o'+'pinion'='OPINION'
Can you help me to learn more?
(Other definitions for opinion that I've seen before include "Unproved belief or view" , "Point of view or thought on something" , "Personal belief or judgment" , "A view held as probable - well, that's mine" , "Viewpoint" .)