night-sight vs sight

night-sight and sight both are nouns.

Word	Noun	Adjective	Verb	Adverb
night-sight	Yes	No	No	No
sight	Yes	No	Yes	No

As nouns, sight is a hypernym of night-sight; that is, sight is a word with a broader meaning than night-sight:

Other hypernyms of night-sight include vision, visual modality, visual sense.

night-sight (noun)	sight (noun)
the ability to see in reduced illumination (as in moonlight)	the act of looking or seeing or observing
	the ability to see; the visual faculty
	an instance of visual perception
	the range of vision
	a range of mental vision
	a place of interest, especially to visitors
	anything that is seen
	(often followed by `of') a large number or amount or extent

night-sight (verb)	sight (verb)
	catch sight of; to perceive with the eyes
	take aim by looking through the sights of a gun (or other device)