Rushes at different rates (5)
I believe the answer is:
tears
'rushes' is the definition.
(tearing is a kind of rushing)
'different rates' is the wordplay.
'different' indicates an anagram.
'rates' with letters rearranged gives 'TEARS'.
'at' acts as a link.
(Other definitions for tears that I've seen before include "exuding drops" , "Water in eyes" , "signs of emotion" , "See 1" , "Lacerations (before bedtime?)" .)