Yardbird is a word that has had several informal meanings.
Naval vessels coming into port for maintenance would be 'descended upon' by crews in the port's maintenance yard. Hence, the ship's crew referred to them as "yardbirds".[
"Yardbird" was the nickname given to two B-17 Flying Fortress bombers of the United States Air Force that flew combat missions over Europe during the Second World War. Both bombers were based at RAF Molesworth in England, as part of the 303d Bombardment Group (Heavy): "Yardbird" (41-24602), piloted by captain John W. Farrar (360th Bombardment Squadron), was shot down by flak and German fighter aircraft on 29 May 1943, near Pleubian, France. "Yardbird II" (42-5620), piloted by 1st Lt. Paul S. Tippet (360th Bombardment Squadron), was shot down by two German fighter aircraft over the North Sea, returning from a successful raid over Emden, on 2 October 1943, with all eleven aboard killed in action. It was one of the group's most successful bombers having completed over 43 missions.
Yardbird is post-Second World War African American slang for a prisoner, from the notion of prison yards.
The Doepke Yardbird was a 1950s hand-cranked, rideable toy train.
Yardbird was the name of a Usenet child pornography ring, an approximate third of whose members were arrested in 2006; the eponymous leader remains at large.