impulse buy
noun [ C ]
ukus(also impulse purchase)something that you buy without having planned it, and without thinking carefully:
I hadn't intended to get another pair of shoes - it was an impulse buy.
impulse buyer
noun [ C ] (also impulse purchaser)
The snack food marketplace is largely an impulse buyers' market.
impulse buying
noun [ U ] (also impulse purchasing)
Supermarkets have reported a huge increase in impulse buying.