Words That Sound Like They Should Have a Direct Antonym but Don't Really.

Otherwise known as "unpaired words" — please add suggestions with sample sentences!
  1. Discombombulate
    "After a good night's rest, I felt so combombulated!"
  2. Disgruntled
    "I've never met such a pleasant and gruntled store clerk!"
  3. Innocent
    "The nocent Mr. Grey looked astonished when he found out Ana was a virgin." Now that I think of it, "nocent" might actually be a word just infrequently used? Not sure.
  4. Ruthless
    "She was the epitome of a ruthful employee, so timid and shy that her coworkers took advantage of her over and over."
  5. Inert
    The ert chemical compound was so volatile that they immediately evacuated the building.
  6. District
    Suggested by   @ChrisK