inflexible vs rock-ribbed

inflexible and rock-ribbed both are adjectives.

Word	Noun	Adjective	Verb	Adverb
inflexible	No	Yes	No	No
rock-ribbed	No	Yes	No	No

inflexible (adjective)	rock-ribbed (adjective)
resistant to being bent	tradition-bound and obstinately opinionated
incapable of change	abounding in or bordered by rocky cliffs or scarps
not making concessions
incapable of adapting or changing to meet circumstances