Pass eccentric asleep (6)
I believe the answer is:
elapse
'pass' is the definition.
(I've seen this before)
'eccentric asleep' is the wordplay.
'eccentric' is an anagram indicator.
'asleep' is an anagram of 'ELAPSE'.
(Other definitions for elapse that I've seen before include "Of time, pass by - please" , "(Of time) go by" , "Passing" , "Please (anag) -- pass away" , "'Pass by, as time (6)'" .)