IPA: /ˈseɪfˌkrækər/
KK: /ˈseɪfˌkrækər/
A person who illegally opens safes to steal the contents inside.
The police caught the safecracker before he could escape with the stolen money.
Safecracker → It is formed from "safe" (from Old French *saf*, meaning secure or protected) and "cracker" (from the verb "to crack", meaning to break open). The word "safecracker" refers to someone who breaks open a safe, typically to steal its contents.
Think of someone who 'breaks open' ('cracker') a 'secure' place ('safe') — that's why a safecracker is someone who opens safes.