WordWeb Online

1. Not diminished or moderated in intensity or severity; sometimes used as an intensifier
   "unmitigated suffering"; "an unmitigated horror"; "an unmitigated lie"

See also: arrant, bally [Brit, informal], blinking [Brit, informal], bloody [Brit, informal], blooming [Brit, informal], bodacious [N. Amer, informal], complete, consummate, crashing, double-dyed, effing [Brit, informal], everlasting, flaming, freaking [informal], gross, perfect, pure, rigorous, sodding, staring, stark, thorough, thoroughgoing, unadulterated, undiminished, unrelieved, utter

Antonym: mitigated