the boot vs iron boot

the boot and iron boot both are nouns.

Word	Noun	Adjective	Verb	Adverb
the boot	Yes	No	No	No
iron boot	Yes	No	No	No

As nouns, the boot and iron boot are synonyms defined as:

the boot and iron boot: an instrument of torture that is used to heat or crush the foot and leg

Other synonyms of the boot include boot, iron heel.

the boot (noun)	iron boot (noun)
an instrument of torture that is used to heat or crush the foot and leg	an instrument of torture that is used to heat or crush the foot and leg