Jailbird and Yard bird

Jailbird noun - A person convicted as a criminal and serving a prison sentence.

Yard bird and jailbird are semantically related. In some cases you can replace phrase "Yard bird" with "Jailbird", this terms are similar.

Yard bird noun - A military recruit who is assigned menial tasks.

Jailbird and yard bird are semantically related. You can use "Jailbird" instead a noun phrase "Yard bird".