2An approximately oval ring of plastic or wood fitting the top of a toilet bowl, typically hinged at the back for lifting, on which a person sits in order to urinate or defecate; a lavatory seat.
Origin
Early 19th century; earliest use found in The Examiner.
Definition of toilet seat in US English:
toilet seat
noun
1A seat for a dressing table.
2An approximately oval ring of plastic or wood fitting the top of a toilet bowl, typically hinged at the back for lifting, on which a person sits in order to urinate or defecate; a lavatory seat.
Origin
Early 19th century; earliest use found in The Examiner.