horsebox vs conveyance

horsebox and conveyance both are nouns.

Word	Noun	Adjective	Verb	Adverb
horsebox	Yes	No	No	No
conveyance	Yes	No	No	No

As nouns, conveyance is a hypernym of horsebox; that is, conveyance is a word with a broader meaning than horsebox:

horsebox: a conveyance (railroad car or trailer) for transporting racehorses
conveyance: something that serves as a means of transportation

Other hypernyms of horsebox include transport.

horsebox (noun)	conveyance (noun)
a conveyance (railroad car or trailer) for transporting racehorses	act of transferring property title from one person to another
	the act of moving something from one location to another
	something that serves as a means of transportation
	the transmission of information
	document effecting a property transfer