Apostolic College refers to the twelve Apostles of Christ

Christ

Christ is the English term for the Greek meaning "the anointed one". It is a translation of the Hebrew , usually transliterated into English as Messiah or Mashiach...

 as the body of men commissioned by Him to spread His message over the whole world and to give it the stability of a well-ordered society: i.e. to be the founders, the foundation, and pillars of the visible church on earth. The name "apostle" denotes their commission. An apostle is a missionary, sent by competent authority, to extend the Gospel

Gospel

A gospel is an account, often written, that describes the life of Jesus of Nazareth. In a more general sense the term "gospel" may refer to the good news message of the New Testament. It is primarily used in reference to the four canonical gospels of Matthew, Mark, Luke, and John...

to new lands. In this context it denotes exclusively Christ's Apostles.