rarity
/ˈreərətɪ/noun
(pl. -ies)［mass noun］
1- the state or quality of being rare稀有, 罕见; 珍奇; 优异：
the rarity of the condition.
难得的状况。
1.1
- count noun a thing that is rare, especially one having particular value as a result of this稀罕的东西, 珍品：
to take the morning off was a rarity.
难得早晨休息。
词源
late Middle English: from Latin raritas, from rarus 'far apart, infrequently found' （see RARE1）.