Fading light aloft grew, somehow (9)
I believe the answer is:
afterglow
'fading light' is the definition.
(I've seen this before)
'aloft grew somehow' is the wordplay.
'somehow' indicates an anagram.
'aloft'+'grew'='aloftgrew'
'aloftgrew' is an anagram of 'AFTERGLOW'.
(Other definitions for afterglow that I've seen before include "following which gloom sets in?" , "Post-sunset radiance" , "The satisfaction" , "Pleasure of remembering something nice" , "trace of sunset" .)