dog-iron vs firedog

dog-iron and firedog both are nouns.

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

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

Other synonyms of dog-iron include andiron, dog.

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