Strong’s Greek
G5431 — phrontizo
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
φροντίζω
phrontizo — pronounced fron-tid'-zo
from a derivative of 5424; to exercise thought, i.e. be anxious:--be careful. see GREEK for 5424
1 occurrence in the KJV.
Titus 3:8
This is a faithful saying, and these things I will that thou affirm constantly, that they which have believed in God might be careful to maintain good works. These things are good and profitable unto men.