稀罕的英文：
rareness
rarity

参考例句：

Hardly ever; very rarely
很少;稀罕

During all the early periods of their development, mirrors were rare and expensive.
在早期发展阶段，镜子既稀罕又珍贵。

I have brought you a rare and noble gift.
我给你们带来一件稀罕而宝贵的礼物。

Vaccination has made smallpox a very rare disease.
接种疫苗已使天花成为一种很稀罕的疾病。

Targets became scarce, and Byron crept here and there off the west coast of honshu, admiring the pretty landscape
目标变得稀罕了，于是拜伦就在本州西海岸以外到处航行，欣赏那些美丽的景色。

It is a curious, interesting, and nearly perished link between obsolete forms of life and those which generally prevail
这是把过去的生活方式和现时一般流行的生活方式联系起来的一个稀罕、有趣、快要绝迹的环节。

rareness是什么意思：
n. 稀罕,珍奇,稀薄

I will have a cheeseburger, medium rare.
我要一份起士汉堡，五分熟。

I rarely have short drinks.
我很少喝烈性酒。

Journalists are rarely admitted to the region.
新闻记者很少获准进入该地区。

Economic collapse is a rare circumstance.
经济崩溃是不太可能发生的事。

It is very rare for Jeanne to be late.
珍妮很少迟到。

rarity是什么意思：
n. 稀有，罕见，稀罕的东西，珍品，稀有物

Such gallantry in men is sadly a rarity.
这般殷勤的男人世间少有。

Rain is a rarity in the desert.
在沙漠中雨是罕见的。

No one discovers a rarity by chance.
侥幸发现一件珍品的人是没有的。

Movie is a rarity in countryside.
电影在农村十分罕见。

These points fully attest to the rarity of the painting.
这也说明此图珍贵之所在。