Apostle Achaicus

The holy, glorious, all-laudable Apostle Achaicus (also Achaikos or Achikos ) of the Seventy is commemorated by the Church on June 15 with Fortunatus and Stephen , and on January 4 with the Seventy.
St. Achaicus is mentioned by St. Paul in I Corinthians 16:17, saying, "I am glad of the coming of Fortunatus and Achaicus: for that which was lacking on your part they have supplied. For they have refreshed my spirit, and yours."

Извор: OrthodoxWiki