captioning

/K AE1 P SH AH0 N IH0 NG/
verb
  1. 1

    To add captions to a text or illustration.

    โ€œOnly once the drawing is done will the letterer caption it.โ€

  2. 2

    To add captions to a film or broadcast.

noun
  1. 1

    The act of assigning a caption.

Source: https://en.wiktionary.org/wiki/caption, https://en.wiktionary.org/wiki/captioning