Strong’s Greek
G2454 — Ioudaismos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
Ἰουδαϊσμός
Ioudaismos — pronounced ee-oo-dah-is-mos'
from 2450; "Judaism", i.e. the Jewish faith and usages:--Jews' religion. see GREEK for 2450
2 occurrences in the KJV.
Galatians 1:13
For ye have heard of my conversation in time past in the Jews’ religion, how that beyond measure I persecuted the church of God, and wasted it:
Galatians 1:14
And profited in the Jews’ religion above many my equals in mine own nation, being more exceedingly zealous of the traditions of my fathers.