Strong’s Greek
G4343 — proskarteresis
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
προσκαρτερήσις
proskarteresis — pronounced pros-kar-ter'-ay-sis
from 4342; persistancy:--perseverance. see GREEK for 4342
1 occurrence in the KJV.
Ephesians 6:18
Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;