overdraw

Short definition from Wiktionary

Verb

1. 1
   To withdraw more money from an account than there is credit; to make an overdraft
2. 2
   To use a device for shooting arrows shorter than the draw of the bow.
3. 3
   To exaggerate.
4. 4
   To draw over the top of existing content.
5. 5
   To draw the air in through a harmonica while adjusting the mouth so that the note goes up a half tone.

Noun

1. 1
   The process by which, during the rendering of a three-dimensional scene, a pixel is replaced by one that is closer to the viewpoint, as determined by their Z coordinates.