Not able to be mitigated; not mitigable.(adjective)
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Use "unmitigable" in a sentence
"Fues Fission says: straws are being grasped-anything goes in covering asses and mitigating the unmitigable."
"Anna should love, and after our love-journey together, go about our separate lives and dine at the public tables, until the advent of her motherhood, would have seemed a terrible strain upon our unmitigable loyalty."
"There a new broom had been brought in, in the place of our poor friend Alaric, a broom which seemed determined to sweep all before it with an unmitigable energy."