Kitchen appliance ultimately useful in drinking-spree (7)
I believe the answer is:
blender
'kitchen appliance' is the definition.
(I've seen this before)
'ultimately useful in drinking-spree' is the wordplay.
'ultimately' indicates one should take the final letters.
'in' means one lot of letters goes inside another.
'drinking spree' becomes 'bender' (I've seen this before).
The final letter of 'useful' is 'l'.
'l' placed into 'bender' is 'BLENDER'.
(Other definitions for blender that I've seen before include "Kitchen machine" , "Good mixer" , "Kitchen device" , "Kitchen appliance" , "used to make assets liquid?" .)