Sixtus I

[siks-tuh s]
Also Xystus I.

Sixtus II

or Xystus II

noun
  1. Saint,died a.d. 258, pope 257–258.

Sixtus III

or Xystus III

noun
  1. Saint, pope a.d. 432–440.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018