The original Japanese title of the Pokémon franchise was “Pocket Monsters.”
In Japanese, the franchise is called Poketto Monsutā, written as ポケットモンスター. Pokémon is the shortened international form of that title. The abbreviation was used globally when the franchise expanded, with an acute accent added to the e in Pokémon to guide pronunciation in many languages.
The first Japanese games were titled Pocket Monsters Red and Green. The animated series also originally used Pocket Monsters as its title in Japan, while international releases generally used Pokémon. The shorter name made the brand easier to recognize and helped distinguish it from unrelated uses of the phrase “pocket monsters.”
The name is sometimes mistaken for a reference to Poké Balls, but the title refers to the creatures themselves and to the idea of carrying them in portable devices. The word Pokémon is also grammatically unchanged in singular and plural usage: both one creature and many creatures are Pokémon.