The name is a shortened form of Micaiah, meaning who is like Jehovah?
(1.) A man of Mount Ephraim, whose history so far is introduced in Judg. 17, apparently for the purpose of leading to an account of the settlement of the tribe of Dan in Northern Palestine, and for the purpose also of illustrating the lawlessness of the times in which he lived (Judg. 18; 19:1-29; 21:25).
(2.) The son of Merib-baal (Mephibosheth), 1 Chr. 8:34, 35.
(3.) The first in rank of the priests of the family of Kohathites (1 Chr. 23:20).
(4.) A descendant of Joel the Reubenite (1 Chr. 5:5).
(5.) The author of the Book of Micah, also called "The Morasthite" to distinguish him from Micaiah, the son of Imlah (1 Kings 22:8). He was a prophet of Judah, a contemporary of Isaiah (Micah 1:1), a native of Moresheth of Gath (1:14, 15). Very little is known of the circumstances of his life (comp. Jer. 26:18, 19).
Initial text from Easton's Bible Dictionary, 1897 -- Please update as needed