Lockman is a term commonly associated with a professional who specializes in securing locks and keys. A locksmith is a synonym for lockman, which originated from the two words "lock" and "smith", which means someone who works with metal. Another synonymous word for lockman is keysmith, who manipulates locks and keys. A safe-cracker is an informal term, which is also a synonym for lockman, implying someone who has the skills and knowledge to crack a safe or vault. A padlock master is another synonym for lockman, which signifies someone who has mastered the art of padlocks. Finally, a tumbler is a less commonly used term for lockman, which refers to someone who picks locks.