Spud dined in extremes of terror! (5)
I believe the answer is:
tater
'spud' is the definition.
(I know that spud can be written as tater)
'dined in extremes of terror' is the wordplay.
'dined' becomes 'ate' (I've seen this in another clue).
'in' indicates putting letters inside.
'extremes of' suggests removing the centre (only the letters at the extremes of the word).
'terror' with its middle removed is 'tr'.
'ate' put into 'tr' is 'TATER'.
(Other definitions for tater that I've seen before include "Charlotte, for example" , "found in vegetable basket" , "Champ is mostly" , "King Edward, for example" , "Potato (colloq.)" .)