Dug under half of shed producing tremor (7)
I believe the answer is:
shudder
'tremor' is the definition.
(synonyms)
'dug under half of shed' is the wordplay.
'dug' becomes 'udder' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'under' is a charade indicator (letters next to each other) (below, in a down clue).
'half of' means to take half the letters.
'shed' cut in half is 'sh'.
'udder' after 'sh' is 'SHUDDER'.
'producing' acts as a link.
Can you help me to learn more?
(Other definitions for shudder that I've seen before include "Shiver in fear or revulsion" , "Convulse" , "Shake with fear" , "Shiver with horror" , "Tremble through fear" .)