Well, let’s look at the definition of Hostage, according to the Merrian-Webster dictionary a Hostage is:

a: a person held by one party in a conflict as a pledge pending the fulfillment of an agreement

b: a person taken by force to secure the taker’s demands

Interesting, let’s look further, at the Encyclopedia Britannica:

a person handed over by one of two belligerents to the other or seized as security for the carrying out of an agreement or for preventing violation of the law of war.

Fascinating. Let’s contrast this with what Britannica says about Political Prisoners:

a person who is imprisoned because that person’s actions or beliefs are contrary to those of his or her government. […] In practice, political prisoners often cannot be distinguished from other types of prisoners.

Well, considering that the majority of Palestinians detained by Israel are held by the army as military prisoners as they are not considered citizens, therefore they didn’t even had any political rights or are considered under the government jurisdiction to begin with anyway. I would say one term applies, but the other doesn’t. I agree that, words do have meanings. You can’t just make up new definitions to suit the situation that best aligns with your politics.