The word that does not belong is "huésped." Explanation:

• "Huésped" means guest or lodger.
• "Cementerio" means cemetery.
• "Tumbas" means tombs or graves.
• "Muertos" means dead people or the deceased.

The last three words (cementerio, tumbas, muertos) are all related to death and burial, while "huésped" refers to a living guest and is unrelated to the others in meaning.