Permutable primes in a given base are prime numbers which are still prime numbers after some nontrivial permutation of their base digits. For example, in base 10, the prime number 137 is still prime after its digits are permuted to 173 (however, note that 371 is not prime since it's equal to 7 × 53).
The term permutable prime has been used to mean primes that remain prime after any permutation of their digits whatsoever. In the OEIS, these are called "absolute primes." Without the repunit primes, the absolute primes are a subset of the permutable primes.