robust vs cast-iron

robust and cast-iron both are adjectives.

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

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