Strong's G15 — ἀγαθοποιέω (verb)
agathopoieo (ag-ath-op-oy-eh'-o) v.
1. to be a well-doer (as a favor or a duty)
[from G17]
KJV: (when) do good (well) 
Root(s): G17 
Hebrew root: ἀγαθοποιός
Occurrences: 9