Cabecera

Perhaps the most common Spanish word for pillow is almohada, but Costa Ricans tend to use cabecera for the pillow that you sleep on. This word should not be confused with cabezazo, which is a header (when you strike the soccer ball with your head).

A funny expression that I picked up in Costa Rica was planchar la oreja, or iron the ear, which one would say before going to bed.

Example: "Tengo sueño. Voy a planchar la oreja."