From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

KJV "the plain" ( Genesis 13:10;  Genesis 13:12). The Hebrew means the "circuit" or low tract round about the Jordan. (See Region Round About )

Smith's Bible Dictionary [2]

Cic'car. See Jordan .

International Standard Bible Encyclopedia [3]

sik´ar ( כּכּר , kikkār , "circle"): Used of the circle of the Jordan ( Genesis 13:10 , Hebrew). See Plain; Cities Of The Plain .

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [4]

( כִּכָּר , Kikkar', Circuit, esp. of the Jordan)

(See Topographical Terms); (See Talent).