adjective / noun
captive
KAP-tiv/kˈæptɪv/
Kept under control or unable to leave or escape.
The captive fox watches the woodland through secure enclosure bars.

Etymology
The root's 'taking' means seizure: the Latin adjective described someone taken prisoner. Used as a noun, it names someone kept in confinement or another's power.
In context
she had been used to move and think freely, she felt as does a captive who has escaped from an irksome durance.
More examples
- The captives waited for release.
- The small town offered a captive market.
- They kept the animal captive during treatment.
Forms
captive · captives
captivity noun — the state of being held