1. Spend more than available of (a budget)
   "The project manager overspent the allocated budget by 20%"; "The government overspent on defence this year"
    
2. Spend at a high rate
   "The tourists overspent on souvenirs"; "He tends to overspend when he goes shopping"

Derived forms: overspent, overspends, overspending

Type of: consume, spend, squander, ware [archaic], waste

Antonym: underspend