European Alps formed eastern pass (6)
I believe the answer is:
elapse
'pass' is the definition.
(I know that pass can be written as elapse)
'european alps formed eastern' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'formed' is an anagram indicator.
'eastern' becomes 'e' ().
'e'+'alps'='ealps'
'ealps' is an anagram of 'elaps'.
'elaps'+'e'='ELAPSE'
(Other definitions for elapse that I've seen before include "Pass or expire - please" , "Of time, pass by - please" , "Tick by" , "Slip away" , "Please (anag) -- pass away" .)