| adjective | not widely known; especially valued for its uncommonness “a rare word” |
| adjective | recurring only at long intervals “a rare appearance” |
| adjective | not widely distributed “rare herbs” |
| adjective | having low density “rare gasses” |
| adjective | marked by an uncommon quality; especially superlative or extreme of its kind; -J.R.Lowell “what is so rare as a day in June” |
| adjective | (of meat) cooked a short time; still red inside “rare roast beef” |
| rareness | noun | noteworthy scarcity |
| rarity | noun | noteworthy scarcity |
| uncommonness | noun | extraordinariness as a consequence of being marked by an uncommon or superlative quality |