Presently being full of whisky, black out (5)
I believe the answer is:
swoon
'black out' is the definition.
(swooning is a kind of blacking out)
'presently being full of whisky' is the wordplay.
'presently' becomes 'soon' ('soon' can be a synonym of 'presently').
'being full of' is an insertion indicator.
'whisky' becomes 'w' (phonetic alphabet: alpha, bravo, charlie etc.).
'soon' going around 'w' is 'SWOON'.
(Other definitions for swoon that I've seen before include "Show ecstasy" , "Pass out" , "Faint (with emotion)" , "Lose consciousness" , "experience ecstasy" .)