Definitely not anyone's favourite thing (apart from the local council — which around here is Caja Municipal Cusco), a multa is a "fine", or "payment penalty". Similarly, the verb multar means "to fine". Someone can "pone una multa a tí" (lit: "give you a fine"), or they can just "te multa" (lit: "fine you"). You can "paga tus multas" (lit: "pay your fines"); or alternatively, you could "pide tus multas" (lit: "lose your fines"). One way or another, they're always a pain in the a$$.