quadruplet

/K W AA0 D R UW1 P L AH0 T/
noun
  1. 1

    One of a group of four babies born from the same mother during the same birth.

  2. 2

    A tuplet of four notes.

  3. 3

    A sequence of four elements.

  4. 4

    A cycle for carrying four riders, arranged so that all the riders can assist in the propulsion.

Source: https://en.wiktionary.org/wiki/quadruplet