Runs in a boy for fire-raising (5)
I believe the answer is:
arson
'fire-raising' is the definition.
('arson' can be a synonym of 'fire-raising')
'runs in a boy' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'in' means one lot of letters goes inside another.
'boy' becomes 'son' ('son' can be a synonym of 'boy'**).
'a'+'son'='ason'
'r' inserted inside 'ason' is 'ARSON'.
'for' is the link.
(Other definitions for arson that I've seen before include "Fire-lighting crime" , "Illegally firing" , "A burning crime" , "Crime involving fire" , "Act of a pyromaniac" .)