Pam struggled in current (3)
I believe the answer is:
amp
'current' is the definition.
(electricity)
'pam struggled' is the wordplay.
'struggled' indicates an anagram (I've seen 'struggling' mean this).
'pam' is an anagram of 'AMP'.
'in' acts as a link.
(Other definitions for amp that I've seen before include "Current measure" , "A flow of one coulomb per second" , "Unit of electricity, in short" , "Current; hi-fi kit" , "Sound-boosting piece of equipment (abbr)" .)