presupuesto
/pɾesuˈpwesto/ · B1 · adj
budget
💰🧾 pre + supuesto (supposed) = what you pre-suppose you'll spend
From Latin praesupponere, to assume in advance. A budget is money you pre-suppose before spending it, which explains the meaning estimate. The older sense, reason or motive, is what you assume beforehand as grounds for acting.