Strong’s Greek
G3145 — massaomai
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
μασάομαι
massaomai — pronounced mas-sah'-om-ahee
from a primary masso (to handle or squeeze); to chew:--gnaw.
1 occurrence in the KJV.
Revelation 16:10
And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain,