Two graduates and bishop gathering round African tree (6)
I believe the answer is:
baobab
'african tree' is the definition.
(I've seen this in another clue)
'two graduates and bishop gathering' is the wordplay.
'two graduates' means two substitutions for 'graduate'.
'graduate' becomes 'BA' (someone with a Bachelor of Arts degree).
'graduate' becomes 'aob' (I am not sure about this - if you are sure you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'bishop' becomes 'B' (abbreviation for bishop in chess).
'gathering' indicates putting letters inside (gather can mean to acquire or bring in).
'aob' put after 'b' is 'baob'.
'ba' put within 'baob' is 'BAOBAB'.
'round' is the link.
I am not very happy about this link. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for baobab that I've seen before include "African fruit tree" , "Monkey-bread tree" , "Gigantic tropical tree with very thick trunk" , "Thick-trunked tree" , "Tree indigenous to Africa and Australia" .)