Requires guts, but no resistance (7)
I believe the answer is:
entails
'requires' is the definition.
(I've seen this in another clue)
'guts but no resistance' is the wordplay.
'guts' becomes 'entrails' (I've seen this before).
'but no' suggests deleting specific letters.
'resistance' becomes 'r' (electronics abbreviation).
'entrails' with 'r' taken out is 'ENTAILS'.
(Other definitions for entails that I've seen before include "Has as a direct consequence" , "limits of will" , "Involves, makes necessary" , "Has as a logical consequence" , "Necessitates" .)