What does "extra" mean?

Extra: Beyond what is due, usual, expected, or necessary; additional; supernumerary; also, extraordinarily good; superior; as, extra work; extra pay. "By working extra hours." H. Spencer.

Additional senses

  1. 2.Something in addition to what is due, expected, or customary; something in addition to the regular charge or compensation, or for which an additional charge is made; as, at European hotels lights are extras. [Colloq.]

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