One tends to make a dash with only half the energy (5)
I believe the answer is:
carer
'one tends' is the definition.
(a carer tends patients)
'a dash with only half the energy' is the wordplay.
'a dash' becomes 'car' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' is an insertion indicator.
'only half' means to take half the letters.
'the energy' becomes 'fire'.
'fire' cut in half is 're'.
'car' enclosing 're' is 'CARER'.
'to make' acts as a link.
(Other definitions for carer that I've seen before include "Attendant in nursing home" , "Invalid's helper" , "Responsible person" , "One attending invalid" , "One tending an invalid" .)