零用 has two related senses: as a verb it means 'to spend money in small sums for everyday incidentals', and as a noun (common in compounds like 零用钱) it means 'pocket money' or 'allowance'. The verb sense focuses on small, casual expenditures — buying snacks, bus fare, small daily items — rather than major purchases. It's less common as a standalone verb; you'll more often see it in 零用钱 or 零花钱.