|Easton's Bible Dictionary|
(1.) The head of the fifteenth sacerdotal course for the temple service (1 Chronicles 24:14).
(2.) A priest who returned from Babylon with Zerubbabel (Nehemiah 12:5, 18).
Int. Standard Bible Encyclopedia
bil'-ga bil'-ga-i (bilgah; bilgay, "cheerfulness"): A priest or priestly family in the time of the Return (Nehemiah 12:5), and (under the form of "Bilgai," Nehemiah 10:8) in the time of Nehemiah. According to 1 Chronicles 24:14, Bilgah is the 15th of the 24 divisions of the priests who officiated in the Temple. In the Septuagint, the names read Belgai, Belga and Balgas. The traditional explanation of the name is "rejuvenation"; modern exegetes explain it as "cheerfulness."
Bilgah (3 Occurrences)
1 Chronicles 24:14 the fifteenth to Bilgah, the sixteenth to Immer, (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Nehemiah 12:5 Mijamin, Maadiah, Bilgah, (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Nehemiah 12:18 of Bilgah, Shammua; of Shemaiah, Jehonathan; (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)