rare, uncommon - marked by an uncommon quality; especially superlative or extreme of its kind; "what is so rare as a day in June"-J.R.Lowell; "a rare skill"; "an uncommon sense of humor"; "she was kind to an uncommon degree" Antonym:ordinary (indirect, via extraordinary)
rare, rarefied, rarified - having low density; "rare gasses"; "lightheaded from the rarefied mountain air" Antonym:thick (indirect, via thin)