hidebound
ˈhʌɪdbaʊnd/Submit
adjective
adjective: hidebound; adjective: hide-bound
unwilling or unable to change because of tradition or convention.
"they are working to change hidebound corporate cultures"
synonyms: conservative, reactionary, conventional, orthodox, fundamentalist, diehard, hard-line, dyed-in-the-wool, ultra-conservative, fixed in one's views, set in one's opinions, set in one's ways;