nighthawk

Short definition from Wiktionary

Noun

1. 1
   A nightjar, especially Caprimulgus europaeus (Eurasian nightjar).
2. 2
   A New World nightjar of the genus Chordeiles, especially Chordeiles minor.
3. 3
   A person whose preference or custom is to remain awake and active during the night and the early morning hours.
4. 4
   A nighthawker (metal detectorist who works illegally at night).
5. 5
   An unlicensed prostitute who worked the roadsides at night.