Observe disheartened elders pray on vacation (4)
I believe the answer is:
espy
'observe' is the definition.
(I've seen this before)
'disheartened elders pray on vacation' is the wordplay.
'disheartened' suggests removing the centre.
'on vacation' means to remove the middle letters.
'elders' with its middle taken out is 'es'.
'pray' with its centre removed is 'py'.
'es'+'py'='ESPY'
(Other definitions for espy that I've seen before include "Watch" , "Detect" , "Pick out at a distance" , "Make out at a distance" , "Perceive" .)