The Spanish word 'momo' comes from Medieval Latin 'Momus', which was the name of the god of mockery in classical mythology. This name itself derives from the Ancient Greek word 'μῶμος' (momos), meaning 'blame, ridicule, or criticism'. Over time, the word evolved in Spanish to refer to a gesture or expression used to make people laugh, maintaining its connection to humor and mockery from its mythological origins.

While 'momo' is a relatively simple Spanish word itself, in modern Spanish slang it has also given rise to terms like 'momear' (to make fun of someone) and 'momoso' (someone who makes funny faces or gestures), though these are less common than the base word 'momo'.

While there aren't many common English words directly related to 'momo', the English word 'momus' is occasionally used as a literary reference to mean 'a critic or carping person', preserving the connection to the ancient god of mockery. The term 'mummer', referring to an actor who performs in traditional mime or masked performance, while not directly related, shares some conceptual overlap in its connection to theatrical gestures and expressions.