Possibly neat drink swallowed by worker (8)
I believe the answer is:
ruminant
'possibly neat' is the definition.
I can't judge whether this defines the answer.
'drink swallowed by worker' is the wordplay.
'drink' becomes 'rum' (rum is a kind of drink).
'swallowed by' becomes 'in' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'worker' becomes 'ant' (worker is a type of ant).
'rum'+'in'+'ant'='RUMINANT'
Can you help me to learn more?
(Other definitions for ruminant that I've seen before include "Cud-chewing animal" , "Mammal that chews the cud" , "Cud chewer" , "One chews the cud" , "Cud-chewing mammal" .)