Wild tiger a setting of priorities (6)
I believe the answer is:
triage
'setting of priorities' is the definition.
(I've seen this in another clue)
'wild tiger a' is the wordplay.
'wild' indicates an anagram.
'tiger'+'a'='tigera'
'tigera' is an anagram of 'TRIAGE'.
(Other definitions for triage that I've seen before include "Hospital reception" , "Assignment of urgency to illnesses" , "Sorting and allocating aid on the basis of need" , "Hospital procedure" , "Selection and allocation for medical aid" .)