THESAURUS
hostage
bail, bond, captive, earnest, earnest money, escrow, gage, guaranty, handsel, hock, mainprise, pawn, pignus, pledge, prisoner, recognizance, replevin, replevy, security, surety, token, token payment, undertaking, vadimonium, vadium
ROGET THESAURUS
hostage
Prisoner
N
prisoner, prisoner of war, POW, captive, inmate, detainee,
hostage, abductee, detenu, close prisoner, jail bird, ticket of leave man, chevronne, imprisoned, in prison, in quod, in durance vile, in limbo, in custody, doing time, in charge, in chains, under lock and key, under hatches, on parole.
Security
N
security, guaranty, guarantee, gage, warranty, bond, tie, pledge, plight, mortgage, collateral, debenture, hypothecation, bill of sale, lien, pawn, pignoration, real security, vadium, stake, deposit, earnest, handsel, caution, promissory note, bill, bill of exchange, I, O, U, personal security, covenant, specialty, parole, acceptance, indorsement, signature, execution, stamp, seal, sponsor, cosponsor, sponsion, sponsorship, surety, bail, mainpernor,
hostage, godchild, godfather, godmother, recognizance, deed of indemnity, covenant of indemnity, authentication, verification, warrant, certificate, voucher, docket, doquet, record, probate, attested copy, receipt, acquittance, quittance, discharge, release, muniment, title deed, instrument, deed, deed poll, assurance, indenture, charter, charter poll, paper, parchment, settlement, will, testament, last will and testament, codicil, bonis avibus, gone where the woodbine twineth.