arms vs blazonry

arms and blazonry both are nouns.

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

As nouns, arms and blazonry are synonyms defined as:

Other synonyms of arms include blazon, coat of arms.

arms (noun)	blazonry (noun)
weapons considered collectively	the official symbols of a family, state, etc.
the official symbols of a family, state, etc.