(n.) A bird confined in a cage; esp. a young bird.

POW bond bondmaid bondman bondslave bondsman bondswoman caged cageling catch chain gang chattel chattel slave churl con concubine confined conquest convict coquette date debt slave detainee detenu disenfranchised enslaved enthralled ex-convict flirt galley slave gaolbird helot homager honey hostage imprisoned in bondage in bonds in captivity in chains in slavery in subjection incarcerated internee jailbird liege liege man liege subject lifer locked up odalisque oppressed parolee peon political prisoner prisoner prisoner of war serf servant slave steady stir bird subject subjected subjugated suppressed sweet patootie sweetheart sweetie theow thrall ticket-of-leave man ticket-of-leaver trusty under the heel under the lash unfree vamp vampire vassal villein