Boy has way to avoid fight (4)
I believe the answer is:
bout
'fight' is the definition.
(as in a bout in boxing)
'boy has way to avoid' is the wordplay.
'boy' becomes 'b' (abbreviation used in schools).
'has' means one lot of letters go next to another.
'way to avoid' becomes 'out' (out can mean a way to get out of something).
'b'+'out'='BOUT'
(Other definitions for bout that I've seen before include "Spell - boxing match" , "Period of activity or boxing contest" , "Short period of intense activity" , "Fit" , "Wrestling/boxing match" .)