Camper excited about measure of current (6)
I believe the answer is:
ampere
'measure of current' is the definition.
(I've seen this in another clue)
'camper excited about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'AMPERE' can be found hidden inside 'camper excited'.
(Other definitions for ampere that I've seen before include "Unit measured by 17 across" , "Current analyst" , "Unit of electrical current" , "Solenoid inventor" , "Current measure" .)