ironing vs garment

ironing and garment both are nouns.

Word	Noun	Adjective	Verb	Adverb
ironing	Yes	No	No	No
garment	Yes	No	Yes	No

As nouns, garment is a hypernym of ironing; that is, garment is a word with a broader meaning than ironing:

Other hypernyms of ironing include household linen, white goods.

ironing (noun)	garment (noun)
the work of using heat to smooth washed clothes in order to remove any wrinkles	an article of clothing
garments (clothes or linens) that are to be (or have been) ironed

ironing (verb)	garment (verb)
	provide with clothes or put clothes on