Strong’s Greek
G2357 — threskos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
θρησκός
threskos — pronounced thrace'-kos
probably from the base of 2360; ceremonious in worship (as demonstrative), i.e. pious:--religious. see GREEK for 2360
1 occurrence in the KJV.
James 1:26
If any man among you seem to be religious, and bridleth not his tongue, but deceiveth his own heart, this man’s religion is vain.