Colony in which everyone drinks thin liquid
I believe the answer is:
anthill
'colony' is the definition.
(I have seen 'colony of insects' mean 'ant hill' so perhaps 'colony' could also mean 'ant hill')
'everyone drinks thin liquid' is the wordplay.
'everyone' becomes 'all' (all people).
'drinks' indicates putting letters inside.
'liquid' indicates anagramming the letters.
'thin' anagrammed gives 'nthi'.
'all' going around 'nthi' is 'ANTHILL'.
'in which' acts as a link.
(Other definitions for anthill that I've seen before include "lots of workers" , "Mound of insects" , "Nest" , "Built-up colony" , "Scene of great activity" .)