Gorgeously-coloured insects surrounding a doctor heading for Oaxaca (10)

I believe the answer is:
flamboyant
'oaxaca' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'gorgeously-coloured insects surrounding a doctor heading' is the wordplay.
I cannot quite see how this works, but
'a' could be 'an' and 'an' is present in the answer.
'doctor' could be 'mb' (Bachelor of Medicine, Medicinae Baccalaureus) and 'mb' is found within the answer.
This explanation may well be incorrect...
'for' is the link.
Can you help me to learn more?
(Other definitions for flamboyant that I've seen before include "Ostentatious, colourful" , "Rich" , "Gay" , "Flashy" , "Exuberant" .)
