Rushes around like a monkey (6)
I believe the answer is:
rhesus
'monkey' is the definition.
(rhesus is a kind of monkey)
'rushes around' is the wordplay.
'around' indicates anagramming the letters.
'rushes' is an anagram of 'RHESUS'.
'like a' is the link.
(Other definitions for rhesus that I've seen before include "Primate" , "Small Asian macaque" , "Small, long-tailed monkey" , "Small macaque monkey" , "Type of small monkey" .)