look up any word, like hipster:
 
1.
A sound which can be paired with what is happening in a film or on TV, and is either visible, or is relevant to the action.

Non-diegetic means a sound that cannot be seen on screen, nor has any direct relevance.
Diegetic:- A war film with people firing guns, and some of the shot sounds can be seen on screen, while others cant, but remain relevant to the action.

Non-Diegetic:- A war film with the sound of a cymbal crashing shortly before someone firing. The sound is not relevant to what is happening, nor is implied to be happening on or off screen.
by MonopolyTycoon February 09, 2010
 
2.
Diegetic, in the cinema, typically refers to the internal world created by the story that the characters themselves experience and encounter: the narrative "space" that includes all the parts of the story, both those that are and those that are not actually shown on the screen (such as events that have led up to the present action; people who are being talked about; or events that are presumed to have happened elsewhere). This word is occasionally used in Jack Johnson's songs.
(from Wikipedia, the free encyclopedia)
Well mama said
You can't believe everything you hear
The diegetic world is so unclear...
by pofke September 16, 2008