cast-iron vs robust

cast-iron and robust both are adjectives.

Word	Noun	Adjective	Verb	Adverb
cast-iron	No	Yes	No	No
robust	No	Yes	No	No

cast-iron (adjective)	robust (adjective)
extremely robust	sturdy and strong in form, constitution, or construction
	strong enough to withstand or overcome intellectual challenges or adversity
	marked by richness and fullness of flavor
	rough and crude