Computer program including everything for vote (6)
I believe the answer is:
ballot
'for vote' is the definition.
(synonyms)
'computer program including everything' is the wordplay.
'computer program' becomes 'bot'.
'including' means one lot of letters goes inside another.
'everything' becomes 'all' (all things).
'bot' placed around 'all' is 'BALLOT'.
(Other definitions for ballot that I've seen before include "The process of voting" , "The process of exercising 20 Down" , "System of voting secretly" , "Voting paper" , "Lottery (eg, for tickets)" .)