ad-libbed

/AE1 D L IH0 B D/
verb
  1. 1

    To improvise all or part of a speech or other performance, especially in comedy.

adjective
  1. 1

    Improvised, or performed without preparation.

Source: https://en.wiktionary.org/wiki/ad-lib, https://en.wiktionary.org/wiki/ad-libbed