It's surprising a parent has the energy (7)
I believe the answer is:
amazing
'it's surprising' is the definition.
(amazing is a kind of surprising)
'a parent has the energy' is the wordplay.
'parent' becomes 'ma' (ma can mean mum or mother).
'has' means one lot of letters go next to another.
'the energy' becomes 'zing' (I've seen this before).
'a'+'ma'+'zing'='AMAZING'
(Other definitions for amazing that I've seen before include "Causing wonder" , "Staggering" , "Very surprising, remarkable" , "Gobsmackingly great!" , "Filling with wonder, a huge surprise" .)