Sleepy, Doc and Sneezy emptied bottles o’ whiskey (6)
I believe the answer is:
drowsy
'sleepy' is the definition.
(thesaurus)
'doc and sneezy emptied bottles o' whiskey' is the wordplay.
'doc' becomes 'dr' ('Dr' can be a synonym of 'doc').
'and' means one lot of letters go next to another.
'emptied' suggests removing the centre.
'bottles' indicates putting letters inside ('bottle' can mean to contain).
'whiskey' becomes 'w' (alpha bravo charlie delta ...).
'sneezy' with its centre taken out is 'sy'.
'dr'+'sy'='drsy'
'o'+'w'='ow'
'drsy' going around 'ow' is 'DROWSY'.
(Other definitions for drowsy that I've seen before include "liable to drop off" , "Dull" , "Sleepy, half-asleep" , "Soporific" , "Wanting to nod off" .)