1
general::
A burden and restraint, as in Karen regarded her job as a ball and chain, but she needed the money. The term, dating from the early 1800s, alludes to chaining a heavy iron ball to a prisoner's leg. Later it was transferred to other kinds of restraining burden.
American Heritage Idioms
2
general::
Phrase(s): ball and chain
1. a wife. (Mostly jocular.) • I’ve got to get home to my ball and chain. • My ball and chain is mad at me. 2. a person’s special burden; a job. (Prisoners sometimes were fettered with a chain attached to a leg on one end and to a heavy metal ball on the other.) • Tom wanted to quit his job. He said he was tired of that old ball and chain. • Mr. Franklin always referred to his wife as his ball and chain.
McGrawhill's American Idioms And Phrasal Verbs