People working together drink to the end of boredom (4)
I believe the answer is:
team
'people working together' is the definition.
(I've seen this before)
'drink to the end of boredom' is the wordplay.
'drink' becomes 'tea' (tea is a kind of drink**).
'to the end of' suggests the final letters.
The final letter of 'boredom' is 'm'.
'tea'+'m'='TEAM'
(Other definitions for team that I've seen before include "Company" , "A cooperative unit" , "Mate for a group of players" , "Competitive side" , "People working together" .)