Apathetic, as unplanned shopping trip, perhaps? (8)
I believe the answer is:
listless
I believe this is a double definition.
'apathetic' is the first definition.
(I've seen this before)
'as unplanned shopping trip perhaps?' is the second definition.
(without a shopping list)
(Other definitions for listless that I've seen before include "Low-spirited" , "Lacking energy or vitality" , "Languid - apathetic" , "Devoid of energy or interest" , "Uninterested" .)