Turf out a hundred boarding European plane (5)
I believe the answer is:
eject
'turf out' is the definition.
('eject' can be a synonym of 'turf out')
'a hundred boarding european plane' is the wordplay.
'a hundred' becomes 'c' (roman numeral).
'boarding' means one lot of letters goes inside another.
'european' becomes 'e' (abbreviation e.g. EU).
'plane' becomes 'jet' (jet plane is a kind of plane).
'e'+'jet'='ejet'
'c' going inside 'ejet' is 'EJECT'.
(Other definitions for eject that I've seen before include "Release a cassette from a video recorder, for instance" , "Turf out" , "Oust" , "Expel, throw out" , "Finally leave plane" .)