Unpacifiable is an adjective used to describe a person or situation that cannot be appeased or calmed down. Synonyms for unpacifiable include unyielding, obstinate, stubborn, inflexible, immovable, adamantine, relentless, implacable, unappeasable, and unrelenting. These words all convey a sense of difficulty in satisfying or calming the subject at hand. Whether dealing with a stubborn child, a disgruntled employee, or a raging storm, using these synonyms can help to add variety to your writing and accurately convey the intensity of the situation. By choosing the right synonyms, you can paint a vivid picture of a person or situation that simply can't be pacified.