carriage vs post chaise

carriage and post chaise both are nouns.

Word	Noun	Adjective	Verb	Adverb
carriage	Yes	No	No	No
post chaise	Yes	No	No	No

As nouns, post chaise is a hyponym of carriage; that is, post chaise is a word with a more specific, narrower meaning than carriage:

carriage: a vehicle with wheels drawn by one or more horses
post chaise: closed horse-drawn carriage with four wheels; formerly used to transport passengers and mail

carriage (noun)	post chaise (noun)
a vehicle with wheels drawn by one or more horses	closed horse-drawn carriage with four wheels; formerly used to transport passengers and mail
a railcar where passengers ride
a machine part that carries something else
a small vehicle with four wheels in which a baby or child is pushed around
characteristic way of bearing one's body