IPA: //daɪˈdʒɛtɪk//
KK: /daɪˈdʒɛtɪk/
Relating to the narrative or story within a film, play, or other media, where the sounds or elements are part of the action and can be perceived by the characters.
The music in the scene was diegetic, meaning the characters could hear it as part of their environment.
Diegetic → It is formed from "diegesis" (from Greek "διήγησις", meaning narration or storytelling) and the suffix "-ic" (meaning pertaining to). The word "diegetic" refers to elements that are part of the narrative or story world in a film or literary work.
Think of 'diegesis' as the storytelling aspect, and remember that 'diegetic' means something that belongs to the story or narrative.