Chuck has brief relationship (5)
I believe the answer is:
fling
This clue is a double definition.
'chuck' is the first definition.
(I know this)
'brief relationship' is the second definition.
(I've seen this before)
'has' acts as a link.
(Other definitions for fling that I've seen before include "Brief amour; throw" , "See 7" , "Toss" , "Brief relationship" , "Try" .)