Rush like wild deer (4)
I believe the answer is:
reed
'rush' is the definition.
(I've seen this before)
'wild deer' is the wordplay.
'wild' indicates an anagram.
'deer' is an anagram of 'REED'.
'like' is the link.
(Other definitions for reed that I've seen before include "Tall grass at water's edge" , "Rush" , "Marsh plant for deer" , "oboe part" , "Grass of marshes" .)