noun: Any of several stout-bodied, gregarious terns of the genera Anous and Procelsterna, found in tropical seas.
noun: (dated) A small two-wheeled vehicle drawn by a single horse.
noun: An inverted pendulum consisting of a short vertical flat spring which supports a rod having a bob at the top; used for detecting and measuring slight horizontal vibrations of a body to which it is attached.
noun: (obsolete, uncountable) An old card game.
noun: (television) A cutaway scene of a television interviewer nodding, used to cover an editing gap in an interview.