Forced clan to run at night (9)
I believe the answer is:
nocturnal
'at night' is the definition.
(I've seen this before)
'forced clan to run' is the wordplay.
'forced' is an anagram indicator.
'clan'+'to'+'run'='clantorun'
'clantorun' with letters rearranged gives 'NOCTURNAL'.
(Other definitions for nocturnal that I've seen before include "going abroad furtively?" , "Appertaining to the night" , "Active at night" , "dark hours?" , "Like owls and badgers" .)