Whisky drunk by companion about start of celebration (6)
I believe the answer is:
scotch
'whisky' is the definition.
(Scotch is an example)
'drunk by companion about start of celebration' is the wordplay.
'drunk by' becomes 'sot' ('sot' can be a synonym of 'drunk'. I am not sure about the 'by' bit.**).
'companion' becomes 'ch' (I've seen this in other clues).
'about' indicates putting letters inside.
'start of' suggests taking the first letters.
The initial letter of 'celebration' is 'c'.
'sot'+'ch'='sotch'
'sotch' enclosing 'c' is 'SCOTCH'.
Can you help me to learn more?
(Other definitions for scotch that I've seen before include "Finish off" , "dish" , "good spirits" , "hard drink" , "Cut - wedge - whisky" .)