despenar

A verb whose meaning splits sharply by region and register: in older or literary Spanish it means to relieve someone of suffering (sacar a alguien de pena), while in Argentina, Paraguay, Peru, and Uruguay it's the standard word for putting a suffering animal out of its misery (despenar a la res, to euthanize/finish off livestock). It's also occasionally used, informally, as a euphemism for killing.

• (Argentina/Uruguay) El veterinario tuvo que despenar al caballo herido. — (Argentina/Uruguay) The vet had to put the injured horse out of its misery.
• (literario) Sus palabras lograron despenar el alma del anciano. — (literary) His words managed to ease the old man's suffering.
• En el campo, despenar un animal agonizante se ve como un acto de compasión. — In the countryside, putting a dying animal out of its misery is seen as an act of mercy.

Assuming despenar always means the livestock-euthanasia sense — outside the Southern Cone that regional meaning may not be recognized at all, and in literary Spanish the word instead means the opposite-feeling "relieve of suffering."