Britons yearn for a conifer (5,4)
I believe the answer is:
scots pine
'a conifer' is the definition.
(Scots pine is an example)
'britons yearn' is the wordplay.
'britons' becomes 'scots' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'yearn' becomes 'pine' (synonyms).
'scots'+'pine'='SCOTS PINE'
'for' is the link.
Can you help me to learn more?
(Other definitions for scots pine that I've seen before include "Kind of 3" , "wood" , "Tree common in the Highlands" , "One may provide deal" , "Coniferous tree" .)