companion vs escort

companion and escort both are nouns.

Word	Noun	Adjective	Verb	Adverb
companion	Yes	No	Yes	No
escort	Yes	No	Yes	No

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

Other hyponyms of companion include date, playfellow, playmate, tovarich, tovarisch.

companion (noun)	escort (noun)
a friend who is frequently in the company of another	the act of accompanying someone or something in order to protect them
one paid to accompany or assist or live with another	a participant in a date
a traveler who accompanies you	someone who escorts and protects a prominent person
	an attendant who is employed to accompany someone

companion (verb)	escort (verb)
be a companion to somebody	accompany as an escort
	conduct someone someplace