Glowing article by doctor breaking fast (7)
I believe the answer is:
lambent
'glowing' is the definition.
(I've seen this before)
'article by doctor breaking fast' is the wordplay.
'article' becomes 'a' (indefinite article).
'by' means one lot of letters go next to another.
'doctor' becomes 'mb' (Bachelor of Medicine, Medicinae Baccalaureus**).
'breaking' is an insertion indicator.
'fast' becomes 'lent' (I've seen this before).
'a'+'mb'='amb'
'amb' inserted within 'lent' is 'LAMBENT'.
(Other definitions for lambent that I've seen before include "Softly bright or radiant; flickering" , "Making stealthy moves" , "Flickering like malt, Ben" , "Of flame or light, playing about a surface" , "Glowing with a soft radiance" .)