Strong's G275 — ἀμέριμνος (adjective)
amerimnos (am-er'-im-nos) adj.
1. not anxious
[from G1 (as a negative particle) and G3308]
KJV: without care(-fulness), secure 
Root(s): G1, G3308 
Hebrew root: μέριμνα
Occurrences: 2