Transients

noun

1. Something which is transient.
2. A transient phenomenon, especially an electric current; a very brief surge.
3. (acoustics) A relatively loud, non-repeating signal in an audio waveform which occurs very quickly, such as the attack of a snare drum.
4. A person who passes through a place for a short time; a traveller; a migrant worker
5. A homeless person.