Mixer (large) swallowed in drinking bout (7)
I believe the answer is:
Here is my best explanation:
'mixer' is the definition.
(I've seen this before)
'large swallowed in drinking bout' is the wordplay.
'large' becomes 'l'.
'swallowed in' means one lot of letters goes inside another.
'drinking bout' becomes 'bender' (I've seen this before).
'l' inserted into 'bender' is 'BLENDER'.
(Other definitions for blender that I've seen before include "Good mixer", "Liquidising device", "Kitchen machine", "Kitchen device", "food mixer", "Kitchen appliance", "Mixer", "Kitchen liquidiser", "Kitchen utensil" and "kitchen equipment".)