Eliminate waste in dry message (5)
I believe the answer is:
tweet
'message' is the definition.
(type of online message)
'eliminate waste in dry' is the wordplay.
I cannot quite see how this works, but
'eliminate' could be 'wee' (weeing is a kind of eliminating) and 'wee' is found within the answer.
'dry' could be 'tt' (abbreviation for teetotal) and 'tt' is found in the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for tweet that I've seen before include "Note of a small bird" , "Twitter" , "call" , "Short message posted on a social network" , "Bird noise" .)