Time in Channel island is bleak (5)
I believe the answer is:
stark
'bleak' is the definition.
(I've seen this before)
'time in channel island' is the wordplay.
'time' becomes 't'.
'in' is an insertion indicator.
'channel island' becomes 'sark' (I've seen this before).
't' placed into 'sark' is 'STARK'.
'is' acts as a link.
(Other definitions for stark that I've seen before include "Plain" , "Utterly" , "Unmitigated" , "Unadorned" , "Arrant" .)