Rephaims

Hawker's Poor Man's Concordance And Dictionary

( Genesis 14:5) Those were probably the same as Moses takes notice of  Deuteronomy 2:10-11, there called Emims, a people great and tall, which in times past, it is said, were called giants, as the Anakims; but the Moabites called them Emims. Rapha means giant, consequently Raphaim makes it plural giants. In the margin of the Bible, ( 2 Samuel 21:18; 2Sa 21:20) to the name of giant in each verse Rapha is preserved.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature

so the Hebrew plural Rephaim (q.v.) is incorrectly pluralized again in English in the A.V. ( Genesis 14:5;  Genesis 15:20).