rock-ribbed
1. [ adjective ] abounding in or bordered by rocky cliffs or scarps
Synonyms: rockbound
Examples:

"the rock-ribbed coast of Maine"

Related terms: cliffy
2. [ adjective ] tradition-bound and obstinately opinionated
Synonyms: die-hard
Examples:

"an inflexible (or die-hard) conservative" "rock-ribbed republican"

Related terms: inflexible