Plant yielding gum out East (4)
I believe the answer is:
geum
'plant' is the definition.
The answer is an example.
'gum out east' is the wordplay.
'out' means one lot of letters goes inside another.
'east' becomes 'e' (synonyms).
'gum' placed around 'e' is 'GEUM'.
'yielding' is the link.
(Other definitions for geum that I've seen before include "Plant, avens" , "Lease to a subtenant" .)