From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Butler. One of the officers of the king's household,  Nehemiah 1:11, who had charge of the wine, and poured it out for the king. The chief butler, as the title signifies, was in charge of the butlers.  Genesis 40:1-13.

Easton's Bible Dictionary [2]

 Genesis 40:1-13 41:9 Mashkeh   1 Kings 10:5 2 Chronicles 9:4 Nehemiah 1:11

Holman Bible Dictionary [3]

 Genesis 40:1-23 Genesis 41:9 1 Kings 10:5 2 Chronicles 9:4 Nehemiah 1:11

Morrish Bible Dictionary [4]

An officer of great importance in Oriental courts: he presented the drinking cup to the king.  Genesis 40:1-23 . Nehemiah held the office at Shushan, and was highly esteemed by the king.  Nehemiah 2:1 .

King James Dictionary [5]

BUT'LER, n. A servant or officer in the houses of princes and great men, whose principal business is to take charge of the liquors,place, &c. Formerly, an officer in the court of France, being the same as the grand echanson or great cup-bearer of the present times.

Webster's Dictionary [6]

(n.) An officer in a king's or a nobleman's household, whose principal business it is to take charge of the liquors, plate, etc.; the head servant in a large house.

People's Dictionary of the Bible [7]

Butler.  Genesis 40:1. See Cup-bearer.

Hastings' Dictionary of the Bible [8]

Butler . See Cupbearer.

International Standard Bible Encyclopedia [9]

but´lẽr  : An officer in households of kings, or other dignitaries, having charge of wines and other potables. משׁקה , mashḳeh , "one who gives drink" (Gen 40:1-23;  Genesis 41:9 ), rendered "cupbearer" in  1 Kings 10:5;  2 Chronicles 9:4;  Nehemiah 1:11 . The office was one of consider ble importance in oriental courts, because of the danger to the king's life through plots of poison, etc. Nehemiah held this position to King Artaxerxes. Wealthy courts, as that of Solomon, usually had more than one ( 1 Kings 10:5 ); over these cupbearers or butlers was the sar ha - mash - ḳı̄m , or chief butler ( Genesis 40:9 ).

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [10]

an honorable officer in the household of Pharaoh, king of Egypt ( Genesis 40:1;  Genesis 40:13). The original word מִשְׁקֶה , Mashkeh', properly signifies Cup-Bearer, as it is elsewhere translated ( 1 Kings 10:5;  2 Chronicles 9:4). The Sept. renders it Ἀρχιοινόχοος , "chief wine-pourer," implying him who had the charge of the rest, which, as appears from  2 Chronicles 9:2, is the true meaning. It was his duty to fill and bear the cup or drinking- vessel to the king. Nehemiah was cup-bearer (q.v.) to King Artaxerxes ( Nehemiah 1:11;  Nehemiah 2:1). (See Banquet).