##### Wiktionary

**sexy prime**

n. (context mathematics English) Either of a pair of prime numbers that differ by six

##### Wikipedia

**Sexy prime**

In mathematics, **sexy primes** are prime numbers that differ from each other by six. For example, the numbers 5 and 11 are both sexy primes, because they differ by 6. If *p* + 2 or *p* + 4 (where *p* is the lower prime) is also prime, then the sexy prime is part of a prime triplet.

The term "sexy prime" stems from the Latin word for six: *sex*.