firedog vs dog-iron

firedog and dog-iron both are nouns.

Word	Noun	Adjective	Verb	Adverb
firedog	Yes	No	No	No
dog-iron	Yes	No	No	No

As nouns, firedog and dog-iron are synonyms defined as:

Other synonyms of firedog include andiron, dog.

firedog (noun)	dog-iron (noun)
metal supports for logs in a fireplace	metal supports for logs in a fireplace