Regret - Vine's Expository Dictionary of New Testament Words
Regret[ A-1,Verb,G3338, metamelomai ]
to regret, to repent one," is translated "to regret" in 2 Corinthians 7:8, RV (twice), AV, "repent." See REPENT.
[ B-1,Adjective,G278, ametameletos ]
"not repented of" (a, negative, and A), is translated "which bringeth no regret" in 2 Corinthians 7:10, RV, said of repentance (AV, "not to be repented of"); elsewhere, in Romans 11:29. See REPENT.