Primate departs tropical tree (8)
I believe the answer is:
tamarind
'tropical tree' is the definition.
(I've seen this before)
'primate departs' is the wordplay.
'primate' becomes 'tamarin' (tamarin is a kind of primate).
'departs' becomes 'd' (common abbreviation e.g. train timetables).
'tamarin'+'d'='TAMARIND'
(Other definitions for tamarind that I've seen before include "Tropical African tree" , "exotic fruit" , "Large tropical seedpod with tangy pulp -- mad train (anag)" , "Tree providing Asian flavouring" , "Indian tree with long brown seed pods" .)