Minister backed intervening in harbour subject to tremors (7)
I believe the answer is:
quavery
'harbour subject to tremors' is the definition.
I can't tell whether this definition defines the answer.
'minister backed intervening in' is the wordplay.
'minister' becomes 'rev' (short for Reverend, a church minister).
'backed' is a reversal indicator.
'intervening' becomes 'quay' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'rev' backwards is 'ver'.
'ver' inserted into 'quay' is 'QUAVERY'.
Can you help me to learn more?
(Other definitions for quavery that I've seen before include "Apt to tremble" , "trembling" .)