Model soldier beginning to get on (7)
I believe the answer is:
paragon
'model' is the definition.
(a paragon is a model example of something)
'soldier beginning to get on' is the wordplay.
'soldier' becomes 'para' (short for paratrouper).
'beginning to' suggests taking the first letters.
The first letter of 'get' is 'g'.
'para'+'g'+'on'='PARAGON'
(Other definitions for paragon that I've seen before include "Perfect diamond" , "A perfect person - pagan or what?" , "Model of conduct" , "Exemplar" , "Model of excellence or perfection" .)