dropout

Short definition from Wiktionary

Noun

1. 1
   Someone who has left an educational institution without completing the course
2. 2
   Someone who has opted out of conventional society.
3. 3
   One who suddenly leaves anything, or the act of doing so.
4. 4
   The slot in the frame that accepts the axles of the wheels.
5. 5
   A damaged portion of a tape or disk, causing a brief omission of audio, video, or data.
6. 6
   Momentary loss of an electronic signal.
7. 7
   A technique for regularizing a neural network by discarding a random subset of its units.