1: νεφρός
(Strong's #3510 — Noun Masculine — nephros — nef-ros' )

"a kidney" (Eng., "nephritis," etc.), usually in the plural, is used metaphorically of "the will and the affections," Revelation 2:23 , "reins" (cp. Psalm 7:9; Jeremiah 11:20; 17:10; 20:12 ). The feelings and emotions were regarded as having their seat in the "kidneys."