I agree with both - context is everything. Yes, 사자 could mean lion, but it could also mean other things.

Hi, Henrik. Korean Words are not like English words. Sometimes English words have many different meaning too. (sometimes totally different!) Korean Words are often with chiness characters. "사자" would be a lion, but it would be 'let's buy' Sometimes it means 'dead man', sometime it means 'four people/nations' if you want to know what exactly it means, you should check the context.

It depends on the context. 사자 means 1. lion 2. envoy,emissary 3. let's buy