Annoying child runs into club (4)
I believe the answer is:
brat
'annoying child' is the definition.
(I've seen this before)
'runs into club' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'into' means one lot of letters goes inside another.
'club' becomes 'bat' (bat is a kind of club).
'r' put into 'bat' is 'BRAT'.
(Other definitions for brat that I've seen before include "Annoying child" , "Horrible child" , "Little terror" , "Brash young type" , "An obnoxious or spoiled child" .)