You use something to refer to a thing, situation, event, or idea, without saying exactly what it is. He realized right away that there was something wrong. There was something vaguely familiar about him. The garden was something special. SOMETHING definition: some thing; a certain undetermined or unspecified thing. See examples of something used in a sentence. Something is a song by the English rock band the Beatles from their 1969 studio album Abbey Road. It was written by George Harrison, the band's lead guitarist. 1. an unspecified or unknown thing; some thing: he knows something you don't; take something warm with you. 2. an unspecified or unknown amount; bit: something less than a hundred. 3. an impressive or important person, thing, or event: isn't that something?. SOMETHING definition: 1. an object, situation, quality, or action that is not exactly known or stated: 2. a thing for…. Learn more. The meaning of SOMETHING is some indeterminate or unspecified thing. How to use something in a sentence. The Beatles performing “Something.” Anthology Collection CD & vinyl box sets out now: .