hostage

A person given as a pledge or security for the performance of the conditions of a treaty or similar agreement, such as to ensure the status of a vassal.

And there with alle was made hostage on bothe partyes and made hit as sure as hit myghte be that whether party had the vyctory soo to ende. "And therewithal was made hostage on both parties, and made it as sure as it might be, that whether party had the victory, so to end."

There are instances in which a state accepted a princess both from Han and from the Hsiung-nu, and "once Lou-lan had surrendered and presented tributary gifts [to the Han emperor], the Hsiung-nu heard of those events and sent out troups to attack [Lou-lan]. Whereupon [the king of] Lou-lan sent one son as a hostage to the Hsiung-nu and one as hostage to Han."

A person seized in order to compel another party to act (or refrain from acting) in a certain way, because of the threat of harm to the hostage.

For example, a subject surprised in the act of robbery may take a hostage to use as a shield.

One of the hostages pretends to be pregnant and is released at Benghazi Airport, where the aircraft refuels.

Something that constrains one's actions because it is at risk.

“Oh, well,” I consented sadly, “the garden will lose half of its charm, but such, I suppose, is my hostage to prosperity.”

I, too, have a hostage to the future in my large family, as you have, and my only personal satisfaction is that I will leave the heritage to them that I did the best I could for a great nation.

One who is compelled by something, especially something that poses a threat; one who is not free to choose their own course of action.

You have a choice in every moment, so you can decide to be a host to God and carry around with you the calmness that is the Tao, or you can be a hostage to your ego, which insists that you can't really help feeling disorderly when you're in circumstances that resemble pandemonium.

For I'm not a stupid man, and in that strange, wonderful moment of sublime and utter bliss, I am aware that such joy has its darker side, and that now, more than ever, I am vulnerable; that I have become in that instant a hostage to Fate and Time and, best and worst of all, to Love.

The condition of being held as security or to compel someone else to act or not act in a particular way.

[…] which number, in Januarye last, the better halfe were already sett free, and departed, and the rest attend the oportunitye of good passadge, except only some few ordayned to bee kept in hostage, for the redemption of Turkes, pretended from us; […]

Technically speaking, the Arnold infant was not "kidnapped" at all. Rather was she seized and held in hostage. The defendant "carried" no one away. It is true that for a brief space of time he "detained" the Arnold infant in the garage, but this act, in and of itself, does not constitute "kidnapping" in the legal sense of the word, since, in reality, he was holding her "in hostage"—as a pledge, or shield, or guarantee of his own safety. The appellant, who had spent some time in the armed forces[,] seized the child and "held her in hostage", just as prisoners of war are held in hostage.

To give (someone or something) as a hostage to (someone or something else).

[…] in voting the prolongation of the military budget on a war estimate for a span of three years, contemplates, it is said, a speedy reoccupation of the six departments of France which were hostaged to the Germans at the termination of the war.

To hold (someone or something) hostage, especially in a way that constrains or controls the person or thing held, or in order to exchange for something else.

Flexibility of hours is now hostaged to availability of work. Yet, despite these obvious drawbacks the appeal to nurses of freelancing seems to live on. The chief advantage of agency work is the lack of commitment or not being bound by contract ...

Thus, via the Arusha Declaration the Tanzania Government were demonstrating that its country's development would not be hostaged to the capriciousness of the West.