When ordered, please pass by (6)
I believe the answer is:
elapse
'pass by' is the definition.
(to elapse is to run out or pass by)
'when ordered please' is the wordplay.
'when ordered' indicates an anagram.
'please' is an anagram of 'ELAPSE'.
(Other definitions for elapse that I've seen before include "run by" , "Go past" , "Pass or expire - please" , "Please (anag) -- pass away" , "pass in silence" .)