Afrikaner doctor brought in by military plane (6)
I believe the answer is:
bomber
'military plane' is the definition.
(I've seen this before)
'afrikaner doctor brought in' is the wordplay.
'afrikaner' becomes 'boer' (synonyms).
'doctor' becomes 'MB' (abbreviation for Bachelor of Medicine).
'brought in' is an insertion indicator.
'boer' going around 'mb' is 'BOMBER'.
'by' is the link.
(Other definitions for bomber that I've seen before include "Aircraft designed to drop high explosives" , "Eg, Lancaster, Vulcan" , "Zip-up garment elasticated at the waist and cuffs" , "It may be smoked" , "warplane" .)