Projection bringing learner honour (4)
I believe the answer is:
lobe
'projection' is the definition.
(I know that lobe is a type of projection)
'learner honour' is the wordplay.
'learner' becomes 'l' (as in a learner driver with L-plates on their car).
'honour' becomes 'obe' (Order of the British Empire award).
'l'+'obe'='LOBE'
'bringing' is the link.
(Other definitions for lobe that I've seen before include "could be site of a 24 [STUD]" , "Appendage to ear" , "Lower part of the ear" , "Rounded part (of organ)" , "Rounded projection of a larger structure" .)