Several doctors, about five, the fellow dismissed (6)
I believe the answer is:
divers
'several' is the definition.
(I've seen this in another clue)
'doctors about five the fellow dismissed' is the wordplay.
'doctors' becomes 'drs' ('Dr' can be a synonym of 'doctor').
'about' indicates putting letters inside.
'the fellow' becomes 'f' (abbreviation - of a society etc.).
'dismissed' indicates named letters should be taken away.
'five' with 'f' removed is 'ive'.
'drs' placed around 'ive' is 'DIVERS'.
(Other definitions for divers that I've seen before include "competitors at the Olympic Games?" , "ducks" , "ducklike birds" , "Plungers" , "Way back, various" .)