European in street with man's horse (5)
I believe the answer is:
steed
'horse' is the definition.
(steed is a kind of horse)
'european in street with man's' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'in' means one lot of letters goes inside another.
'street' becomes 'st' (abbreviation).
'with' is a charade indicator (letters next to each other).
'man' becomes 'ed' (short for Edward).
'st'+'ed'='sted'
'e' inserted inside 'sted' is 'STEED'.
(Other definitions for steed that I've seen before include "Warhorse" , "Swift horse" , "(Poetic) horse" , "Literary term for horse" , "Stallion" .)