Making fast call after beastly sound (7)
I believe the answer is:
mooring
'making fast' is the definition.
(mooring is a kind of making fast)
'call after beastly sound' is the wordplay.
'call' becomes 'ring' (telephone call).
'after' means one lot of letters go next to another.
'beastly sound' becomes 'moo' (moo is a kind of sound. I am not sure about the 'beastly' bit.).
'ring' after 'moo' is 'MOORING'.
Can you help me to learn more?
(Other definitions for mooring that I've seen before include "Tying up a ship" , "where boat is secured" , "stopping" , "Place for anchoring or tying up" , "Ship's berth" .)