Neat tequila is drunk initially - why, you say? (4)
I believe the answer is:
Here is my best explanation:
'neat' is the definition.
('tidy' can be similar in meaning to 'neat')
'tequila is drunk initially why you say?' is the wordplay.
'initially' suggests taking the first letters.
'you say?' indicates a 'sounds like' (homophone) clue.
The initial letters of 'tequila is drunk' is 'tid'.
'why' is a homophone of 'y'.
(Other definitions for tidy that I've seen before include "Ordered", "small container in which odds and ends are kept", "Uncluttered", "Orderly", "Businesslike", "Clear up", "Neat, ordered", "Fairly big - orderly", "generous" and "so substantial a sum".)