ANTIMUS, bishop of NICOMEDIA. — Prelate of that city in Bithynia, martyred at the beginning of the 4th century (3 Sept. 302?) during the persecution of Diocletian. His feast is celebrated on 27 April. A fragment of a work *De sancta ecclesia* survives from him, in which the characteristics defining the true Church in contrast to heretical sects are set forth: unity, catholicity, apostolicity. The fragment is almost certainly interpolated, since it names persons (Astero the Sophist and Eusebius of Caesarea) who lived after A. It is not however established that the inauthenticity of this passage implies that of the rest of the work, which is unknown to us.
BIBL.: G. Mercati, *Note di letteratura biblica e cristiana antica* (*Studi e testi*, 5), Rome 1901, pp. 87–89; O. Bardenhewer, *Geschichte der altchristlichen Literatur*, II, 2nd ed., Freiburg im Br. 1914, pp. 333–34. Mario Niccoli