rarity

1. N-COUNT If someone or something is a rarity, they are interesting or valuable because they are so unusual. 稀有物; 罕見之人[journalism]

Sontag has always been that rarity, a glamorous intellectual. 桑塔格一直都是那種與衆不同、極有魅力的知識分子。

2. N-UNCOUNT The rarity of something is the fact that it is very uncommon. 稀有

It was a real prize due to its rarity and good condition. 它是一件真正的稀世珍品，因爲它不但稀有而且保存完好。