listening watch vs vigil

listening watch and vigil both are nouns.

Word	Noun	Adjective	Verb	Adverb
listening watch	Yes	No	No	No
vigil	Yes	No	No	No

As nouns, vigil is a hypernym of listening watch; that is, vigil is a word with a broader meaning than listening watch:

listening watch: a watch established for the reception of traffic of interest to the unit maintaining the watch
vigil: a purposeful surveillance to guard or observe

Other hypernyms of listening watch include watch.

listening watch (noun)	vigil (noun)
a watch established for the reception of traffic of interest to the unit maintaining the watch	a purposeful surveillance to guard or observe
	the rite of staying awake for devotional purposes (especially on the eve of a religious festival)
	a period of sleeplessness