Tree of greater age (5)
I believe the answer is:
elder
This clue is a double definition.
'tree' is the first definition.
(elder is a kind of tree)
'of greater age' is the second definition.
(I've seen this before)
(Other definitions for elder that I've seen before include "Shrub, tree" , "Patriarch" , "could be a church leader" , "Tree; of greater age" , "Older person - one's senior" .)