From kaphal; a duplicate -- double.
see HEBREW kaphal
H3718. kephel
כֶּ֫פֶל noun [masculine] the double: — ׳כ construct: רִסְנוֺ ׳בְּכ Job 41:5 within the double of his jaw (i.e. his double jaws) who can come ? elsewhere dual כִּפְלַיִם (compare Arabic ), לְתוּשִׁיָּה 11:6 double in sound wisdom (beyond what Job imagines), of retribution Isaiah 40:2.