nighthawk

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several chiefly nocturnal birds of the genus Chordeiles, especially C. minor, having mottled grayish-brown feathers with a white spot on the wings. Also called bullbat, mosquito hawk.
2. n. The European nightjar.
3. n. Informal A night owl.

Century Dictionary and Cyclopedia

1. n. A caprimulgine bird of the genus Chordeiles. The common night-hawk of the United states is C. popetue or C. virginianus, also called bullbat, and in the West lndies pisk: and piramidig. It flies chiefly toward evening and in cloudy weather, and belongs to the same family (Caprimulgidæ) as the whippoorwill and chuck-will's-widow, though it is of a different genus. It is 9 or 10 inches long, 23 in extent of wings, of a slim form, with very small bill but widely cleft and capacious month, long, sharp, thin-bladed wings, forked tail, and small weak feet; the plumage is intimately blended with black, brown, gray, and tawny shades, something like dark-veined marble, and the male has a pure white V-shaped mark on the throat, and large white blotches on the wings and tail, which are tawny in the female. It abounds in temperate North America, and is a bird of powerful flight, often seen careering in pursuit of insects, twisting and doubling with great ease and grace, and frequently falling through the air with a hoarse cry. It lays two eggs of elliptical form and dark variegated color, placing them on the ground with little or no nest. The bird is migratory, and retires beyond the United States in the autumn. There are several other species of the same genus, as C. henryi and C. texensis.
2. n. The night-jar or goatsucker, Caprimulgus curopæus.
3. n. One of certain petrels of the genus Œstrelata: as, the white night-hawk or mutton-bird, Œ. lessoni.
4. n. One who prowls about at night; specifically, a night cabman or his cab or horse.

Wiktionary

1. n. A New World nightjar.
2. n. A person whose preference or custom is to remain awake and active during the night and the early morning hours.

GNU Webster's 1913

1. n. (Zoöl.) an American bird (Chordeiles Virginianus), allied to the goatsucker. It hunts the insects on which it feeds toward evening, on the wing, and often, diving down perpendicularly, produces a loud whirring sound, like that of a spinning wheel.
2. n. A person who likes to be active late at night; a night owl.
3. n. (Zoöl.) Any of several mainly nocturnal North American goatsuckers, especially Chordeiles minor, or the related European goatsucker Caprimulgus europaeus, also called the nightjar.

WordNet 3.0

1. n. mainly nocturnal North American goatsucker
2. n. a person who likes to be active late at night