heraldry vs blazonry

heraldry and blazonry both are nouns.

Word	Noun	Adjective	Verb	Adverb
heraldry	Yes	No	No	No
blazonry	Yes	No	No	No

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

Other hyponyms of heraldry include armorial bearing, bearing, charge, heraldic bearing, arms, blazon, coat of arms.

heraldry (noun)	blazonry (noun)
emblem indicating the right of a person to bear arms	the official symbols of a family, state, etc.
the study and classification of armorial bearings and the tracing of genealogies