yardbird

Etymology

From yard + bird. Attested since 1956 in the sense of ‘convict,’ derived from the idea of prison yards. During World War II, it meant ‘basic trainee’ among the armed forces.

noun

1. (chiefly US, slang) A chicken.
2. (chiefly US, slang) A person who is imprisoned.
   The working convict is a rare exception, sometimes envied because his time is occupied, sometimes derided for his deviance from the yardbird norm. 1985, John P. Conrad, “Charting a Course for Imprisonment Policy,”, in Annals of the American Academy of Political and Social Science, volume 478, page 126
3. (chiefly US, slang) A soldier who is required to perform menial work on the grounds of a military base.
   As the Marines expanded to war strength, Lou Diamond was the ideal liaison between crusty old-timers and impressionable recruits. He taught quick action by threats of yardbird detail. 5 Jul 1943, “In the Rough”, in Time