field trip vs junket

field trip and junket both are nouns.

Word	Noun	Adjective	Verb	Adverb
field trip	Yes	No	No	No
junket	Yes	No	Yes	No

As nouns, junket is a hypernym of field trip; that is, junket is a word with a broader meaning than field trip:

field trip: a group excursion (to a museum or the woods or some historic place) for firsthand examination
junket: a journey taken for pleasure

Other hypernyms of field trip include excursion, expedition, jaunt, outing, pleasure trip, sashay.

field trip (noun)	junket (noun)
a group excursion (to a museum or the woods or some historic place) for firsthand examination	a journey taken for pleasure
	a trip taken by an official at public expense
	dessert made of sweetened milk coagulated with rennet

field trip (verb)	junket (verb)
	partake in a feast or banquet
	provide a feast or banquet for
	go on a pleasure trip