What it is to be loaded? (4)
I believe the answer is:
ammo
'what it is to be loaded?' is the definition.
I can't tell whether this defines the answer.
'what it is to be' is the wordplay.
'what it is' becomes 'mo' (I can't justify this - if you can you should give a lot more credence to this answer).
'to' says to put letters next to each other (I've seen this in other clues).
'be' becomes 'am'.
'mo' put after 'am' is 'AMMO'.
Can you help me to learn more?
(Other definitions for ammo that I've seen before include "Slugs perhaps" , "Bullets (sl.)" , "Bullets, say, in short" , "Bullets, shells (colloq.)" , "Bullets and bombs, etc (abbr)" .)