way station vs flag stop

way station and flag stop both are nouns.

Word	Noun	Adjective	Verb	Adverb
way station	Yes	No	No	No
flag stop	Yes	No	No	No

As nouns, way station and flag stop are synonyms defined as:

way station and flag stop: a small railway station between the principal stations or a station where the train stops only on a signal

Other synonyms of way station include whistle stop.

way station (noun)	flag stop (noun)
a small railway station between the principal stations or a station where the train stops only on a signal	a small railway station between the principal stations or a station where the train stops only on a signal
a stopping place on a journey