(Σάραπις), or SARA'PIS, an Egyptian divinity, the worship of which was introduced into Greece in the time of the Ptolemies. Apollodorus (ii. 50.1) states that Serapis was the name given to Apis after his death and deification. (Comp. Callim. Ep. 39, and Isis.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890