Whisky and mead oddly left at the end of banquet (4)
I believe the answer is:
malt
'whisky' is the definition.
(malt whisky is a kind of whisky)
'mead oddly left at the end of banquet' is the wordplay.
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
'left' becomes 'l' (common abbreviation).
'at the end of' indicates one should take the final letters.
The last letter of 'banquet' is 't'.
The alternating letters of 'mead' are 'ma'.
'ma'+'l'+'t'='MALT'
'and' acts as a link.
(Other definitions for malt that I've seen before include "Ingredient of beer" , "Germinated and kiln-dried grain used in brewing and distilling" , "Whisky ingredient" , "Brewing agent" , "Grain prepared for brewing or distilling" .)