Smith's Bible Dictionary (1863)
(leader of the chorus), one of the seven deacons, being the third of the list, and named next after Stephen and Philip.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
PROCH'ORUS (leader of the chorus), one of the seven deacons. Acts 6:5.
Hitchcock's Bible Names (1869)
he that presides over the choirs