Order vs reader

Order and reader both are nouns.

Word	Noun	Adjective	Verb	Adverb
Order	Yes	No	No	No
reader	Yes	No	No	No

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

Order: (usually plural) the status or rank or office of a Christian clergyman in an ecclesiastical hierarchy
reader: someone who reads the lessons in a church service; someone ordained in a minor order of the Roman Catholic Church

Other hyponyms of Order include acolyte, anagnost, deacon, doorkeeper, ostiarius, ostiary, exorcist, lector, priest, subdeacon.

Order (noun)	reader (noun)
(usually plural) the status or rank or office of a Christian clergyman in an ecclesiastical hierarchy	one of a series of texts for students learning to read
	a person who enjoys reading
	a public lecturer at certain universities
	someone who contracts to receive and pay for a service or a certain number of issues of a publication
	a person who can read; a literate person
	someone who reads proof in order to find errors and mark corrections
	someone who reads manuscripts and judges their suitability for publication
	someone who reads the lessons in a church service; someone ordained in a minor order of the Roman Catholic Church