Stream runs poorly (4)
I believe the answer is:
rill
'stream' is the definition.
(rill is a kind of stream)
'runs poorly' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'poorly' becomes 'ill' ('ill' can be a synonym of 'poorly').
'r'+'ill'='RILL'
(Other definitions for rill that I've seen before include "Flowing water" , "Flow of water" , "Small brook" , "Burn" , "Brooklet" .)