Strong’s Hebrew
H3688 — kacal
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
כָּסַל
kacal — pronounced kaw-sal
a primitive root; properly, to be fat, i.e. (figuratively) silly:--be foolish.
1 occurrence in the KJV.
Jeremiah 10:8
But they are altogether brutish and foolish: the stock is a doctrine of vanities.