Boyd’s Bible Dictionary:
(hollow). Bird-trap (Jer. 5:27); prison (Rev. 18:2).
Concise Bible Dictionary:
It is said symbolically that as a cage or trap is full of birds, so the houses of the Jews were full of deceit (Jer. 5:27). “A cage of every unclean and hateful bird,” is a character a mystical Babylon (Rev. 18:2). The word here is θυλακή, often translated “prison.”