Equal with a soldier (4)
I believe the answer is:
para
'soldier' is the definition.
(paratrooper)
'equal with a' is the wordplay.
'equal' becomes 'par' ().
'with' means one lot of letters go next to another.
'par'+'a'='PARA'
(Other definitions for para that I've seen before include "Soldier who's dropped in? (abbr)" , "Soldier who jumps to order? (abbr)" , "A block of text; an airborne soldier (abbrs.)" , "Soldier in an airborne unit" , "Soldier that jumps from planes" .)