From BiblePortal Wikipedia

Smith's Bible Dictionary [1]

Car'cas. (Severe). The seventh of the seven "chamberlains," that is, eunuchs, of King Ahasuerus.  Esther 1:10. (B.C. 483).

Holman Bible Dictionary [2]

 Esther 1:10AbagthaEsther

Hastings' Dictionary of the Bible [3]

Carcas (  Esther 1:10 ). One of the seven eunuchs or chamberlains of king Ahasuerus.

Morrish Bible Dictionary [4]

Chamberlain of Ahasuerus.  Esther 1:10 .

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [5]

(Hebrews כִּרְכִּס , Karkas', comp. the Sanscrit Karkafa, Severe; Sept. Θαβάζ v. r. Θαραβά , Vulg. Charchas), the last named of the seven eunuchs ("chamberlains") in the harem of Ahasuerus (Xerxes), who were directed to bring queen Vashti into the royal convivial party ( Esther 1:10). B.C. 483.

International Standard Bible Encyclopedia [6]

kar´kas ( כּרכּס , karkaṣ ): One of seven chamberlains, ordered to summon Queen Vashti before King Ahasuerus ( Esther 1:10 ). The Targum allegorizes the first five of the names.