Alexander imbibing hot drink (6)
I believe the answer is:
shandy
'drink' is the definition.
(shandy is a kind of drink)
'alexander imbibing hot' is the wordplay.
'alexander' becomes 'Sandy' (nickname for Alexander).
'imbibing' is an insertion indicator.
'hot' becomes 'h' (abbreviation eg on taps).
'sandy' enclosing 'h' is 'SHANDY'.
(Other definitions for shandy that I've seen before include "Beer and lemonade mixture" , "Beer and lemonade mix" , "Beer/lemonade drink" , "Lemonade-beer drink" , "Weakly-alcoholic drink" .)