Glasses of police constable without energy on board (5)
I believe the answer is:
specs
'glasses' is the definition.
(short for spectacles)
'police constable without energy on board' is the wordplay.
'police' becomes 'ss' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'constable' becomes 'PC' (police constable).
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'energy' becomes 'e' (physics symbol as in E=mcs).
'on board' indicates putting letters inside (inserted letters are taken on board).
'pc' enclosing 'e' is 'pec'.
'ss' going around 'pec' is 'SPECS'.
'of' is the link.
Can you help me to learn more?
(Other definitions for specs that I've seen before include "Instructions" , "you can see right through them" , "Details for designer" , "what builders are doing?" , "Do they help one to see" .)