noun, plural rar·i·ties.
- something rare, unusual, or uncommon: Snowstorms are a rarity in the South.
- something esteemed or interesting in being rare, uncommon, or curious: That folio is a rarity that will bring a good price.
- the state or quality of being rare.
- rare occurrence; infrequency: Volcanic eruptions on the island occur with great rarity.
- unusual excellence.
- thinness, as of air or a gas.
noun plural -ties
- a rare person or thing, esp something interesting or valued because it is uncommon
- the state or quality of being rare
early 15c., “thinness;” 1550s, “fewness,” from Middle French rarité or directly from Latin raritas “thinness, looseness of texture; fewness,” from rarus (see rare (adj.1)). Sense of “a rare thing or event” is from 1590s.