noun

1. Acting automatically or involuntarily.

2. The power of initiating vital processes from within the cell, organ, or organism, independent of external stimulus.

3. The doctrine that animals are automata, operating according to mechanical laws.

4. An action performed subconsciously, without any apparent direction from the mind; a thought which appears spontaneously in one's consciousness.

5. A surrealist painting technique whereby one attempts to move the brush, pen etc. without conscious control over it.