noun

• (uncountable) A stylised Japanese form of wrestling in which a wrestler loses if he is forced from the ring, or if any part of his body except the soles of his feet touches the ground.
• (countable, colloquial) A rikishi (sumo wrestler)
• A Misumalpan language of Nicaragua.
• (biochemistry) Abbreviation of small ubiquitin-related modifier. [A SUMO protein]
• (fandom slang) Abbreviation of Pokémon Sun and Moon.