birdcage hype, n. — Green’s Dictionary of Slang

birdcage hype n.

[? birdcage n. (8) + hype n.² (2); note Maurer ‘Language of the Und. Narcotic Addict’ (1938): ‘Probably so-called because this type of addict often lives in a bird-cage or bird-cage joint, a very cheap lodging house with chicken-wire netting separating the small sleeping compartments. Transients who live in these establishments are called bird-cage stiffs. There is also a saying that when an underworld addict is down and out, “he has a bird cage on one foot and a boxing glove on the other” – a humorous variant of “a boot on one foot and a shoe on the other”’]

(US drugs) the lowest class of heroin addict.

1937		B. Dai Opium Addiction in Chicago 196: Bird-cage hype. The poorer class of addict.
1938		D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981) 99/1: bird-cage hype. A very poor underworld addict who has trouble supporting his habit.
1949		Monteleone Criminal Sl. (rev. edn).
1959		Murtagh & Harris Who Live In Shadow (1960) 17: He is what is known around Junktown as a birdcage hype.