Orange or olive (4)
I believe the answer is:
tree
This clue is a double definition.
'orange' is the first definition.
(thesaurus)
'olive' is the second definition.
(thesaurus)
(Other definitions for tree that I've seen before include "Plane, e.g." , "Large woody plant (4)" , "Large growth" , "Eg, laburnum" , "Birch, say" .)