The word "in-terminable" refers to something that seems endless or without any possibility of coming to an end. The possible antonyms of this word could be terminable, finite, or limited. These words mean that something has a definite end-point and is bound by some form of restriction. The opposite of in-terminable can also mean that something is temporary, brief, or fleeting. Therefore, using the correct antonym can completely change the meaning of a sentence. Using antonyms like terminating, limited, or temporary, can express that something will come to an end or is restricted, whereas in-terminable means the opposite of this.