noun
captor
KAP-ter/ˈkæptər/
A person who captures or holds someone prisoner.
The prisoner’s captor holds the key outside the barred cell.

Etymology
A captor is literally a taker or catcher. In the prisoner sense, taking someone by force or trickery connects the act of seizure with holding that person afterward.
In context
Sansa was a hostage of the crown, at the mercy of the Lannisters — wearing dresses that mirrored her captor Cersei.
More examples
- Her captors moved her to another room.
- The escaped prisoner identified his captor.
- The captor demanded a ransom.
Forms
captor · captors
Similar words
- jailer
- A jailer guards prisoners in an institution; a captor is whoever captures or holds someone.
- kidnapper
- A kidnapper unlawfully abducts someone; captor is broader and need not imply kidnapping.