journey vs expedition

journey and expedition both are nouns.

Word	Noun	Adjective	Verb	Adverb
journey	Yes	No	Yes	No
expedition	Yes	No	No	No

As nouns, expedition is a hyponym of journey; that is, expedition is a word with a more specific, narrower meaning than journey:

journey (noun)	expedition (noun)
the act of traveling from one place to another	a journey organized for a particular purpose
	a military campaign designed to achieve a specific objective in a foreign country
	a journey taken for pleasure
	the property of being prompt and efficient
	an organized group of people undertaking a journey for a particular purpose

journey (verb)	expedition (verb)
undertake a journey or trip
travel upon or across