Strong's Definition
a primitive root; to fold together; figuratively, to repeat
KJV Usage: double
STEPBible — Tyndale Abridged Hebrew Lexicon
כָּפַל (ka.phal) — to double. 1) to double, fold double, double over 1a) (Qal) to double over 1b) (Niphal) to be doubled
UBS Dictionary of Biblical Hebrew
UBS Dictionary of Biblical Hebrew © United Bible Societies, licensed CC BY-SA 4.0.
Brown-Driver-Briggs Hebrew Lexicon
כָּפַל vb. double, double over (late) Qal and thou shalt double over the sixth curtain, i.e. prob. use it double; folded double, of the breast-piece
Niph. and let the sword be doubled, but very dub.
base