Strong’s Greek
G1450 — egguos
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
ἔγγυος
egguos — pronounced eng'-goo-os
from 1722 and guion (a limb); pledged (as if articulated by a member), i.e. a bondsman:--surety. see GREEK for 1722
1 occurrence in the KJV.
Hebrews 7:22
By so much was Jesus made a surety of a better testament.