literally: one sent forth; a messenger. specifically: one of the twelve disciples of christ, specially chosen as his companions and witnesses, and sent forth to preach the gospel.-the missionary who first plants the christian faith in any part of the world; also, one who initiates any great moral reform, or first advocates any important belief; one who has extraordinary success as a missionary or reformer; as, dionysius of corinth is called the apostle of france, john eliot the apostle to the indians, theobald mathew the apostle of temperance.-a brief letter dimissory sent by a court appealed from to the superior court, stating the case, etc.; a paper sent up on appeals in the admiralty courts.