supplemental

/S AH0 P L AH0 M EH1 N T AH0 L/
noun
  1. 1

    Something that supplements or adds to.

  2. 2

    A requisition or article of legislation that provides additional funding for a program.

adjective
  1. 1

    Acting to supplement.

  2. 2

    Appending.

  3. 3

    Lacking a regular schedule (as in a supplemental airline).

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