Strong's #6949: qahah (pronounced kaw-haw')

a primitive root; to be dull:--be set on edge, be blunt.

Brown-Driver-Briggs Hebrew Lexicon:

qâhâh

1) to be blunt, be dull

1a) (Qal) to be blunt, be dull

1b) (Piel) to be blunt

Part of Speech: verb

Relation: a primitive root

Usage:

This word is used 4 times:

 

Ecclesiastes 10:10: "If the iron be blunt, and he do not whet the edge, then must he put to"
Jeremiah 31:29: "a sour grape, and the children's teeth are set on edge."
Jeremiah 31:30: "man that eateth the sour grape, his teeth shall be set on edge."
Ezekiel 18:2: "sour grapes, and the children's teeth are set on edge?"