caged bird
Literal meaning: a bird kept in a cage. Also used metaphorically for a person confined or lacking freedom.
A caged bird does not know the outside world.
person whose freedom is restricted; kept woman
Idiomatic use referring to a person, especially a woman (prostitute, mistress, concubine), whose life is controlled and confined by someone else.
She lived a life just like a caged bird.
Standard kanji spelling using 籠.
Search-only kana form; not a common practical spelling.
Variant kanji spelling using 篭, which is a simplified form of 籠.
Compound of 籠 (かご, 'cage') + の (possessive particle) + 鳥 (とり, 'bird'). The idiomatic sense is a metaphorical extension of the literal meaning.