Why Is a Safe Cracker Called a Yegg?

The word “yegg” soon came to mean a burglar or a safecracker, a usage that's also of uncertain origin, though there are several theories about its orgin. The most common suggestion is that this slang usage is derived from John Yegg, the alias of a bank robber in the late 19th and early 20th centuries.

What does a yegg mean?

yegg \YEG\ noun. : one that breaks open safes to steal : safecracker; also : robber.

What is the word for a safecracker?

safebreaker, safecracker, cracksmannoun. a thief who breaks open safes to steal valuable contents. Synonyms: cracksman, safebreaker.