iron boot vs the boot

iron boot and the boot both are nouns.

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

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

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

Other synonyms of iron boot include boot, iron heel.

iron boot (noun)	the 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