고지식해요 · 고지식했어요 · 고지식한 (+noun)
rigid, inflexible, straitlaced
Example
우리 할아버지는 좀 고지식하셔서 규칙을 꼭 지키세요.
My grandfather is a bit rigid, so he always follows the rules.
Word parts
Despite the look, probably unrelated to 지식 'knowledge'; it's a native word.
Good to know
Not a harsh insult, but implies sticking to rules or principles without any flexibility.
Related words