First-rate illumination for landing (9)
I believe the answer is:
alighting
'landing' is the definition.
(alighting is a kind of landing)
'first-rate illumination' is the wordplay.
'first-rate' becomes 'a' ().
'illumination' becomes 'lighting' (lighting is a kind of illumination).
'a'+'lighting'='ALIGHTING'
'for' acts as a link.
(Other definitions for alighting that I've seen before include "Landing" , "Getting off" , "Descending from a train, bus, etc." , "coming" , "Settling" .)