gastar
transitive verb
1. to spend (consumir) (dinero, tiempo) ; to use (up) (gasolina, electricidad) ; to wear out (ropa, zapatos)
2. to waste (malgastar) (dinero, energía)
3. to wear (tener, usar) (ropa) (peninsular Spanish) ; to take (número de zapatos)
gastar mal genio -> to have a bad temper
4. (hacer)
gastar una broma (a alguien) -> to play a joke (on somebody) (peninsular Spanish)
also:
gastarlas -> to carry on, to behave (peninsular Spanish)
¡no sabes cómo se las gastan allí! -> you can't imagine how they carry on there!
intransitive verb
5. to spend (money)
gastarse
pronomial verb
1. to wear out (deteriorarse, desgastarse)
2. to run out (consumirse)
se han gastado las pilas -> the batteries have run out o gone dead
3. to spend (dinero)
nos gastamos veinte pesos en comida -> we spent twenty pesos on food