Greek: λοιδορια [loidoria] (Noun feminine). From λοιδορος [loidoros]. Objection or criticism in bitter, harsh, or abusive language. Railing, abuse, reviling, reproach. Slander, vituperation.

λοιδορια [loidoria] appears 3 times in the NT:

(1) 1 Timothy 5: 14
I will therefore that the younger women marry, bear children, guide the house, give none occasion to the adversary to speak reproachfully*. - λοιδοριας [loidorias] Gen. sing. (*"to speak reproachfully" - λοιδοριας χαριν [loidorias charin] Lit: "reviling favor" = "for reviling").

(2, 3) 1 Peter 3: 9
Not rendering evil for evil, or railing¹ for railing²: but contrariwise blessing; knowing that ye are thereunto called, that ye should inherit a blessing. - ¹λοιδοριαν [loidorian] Accus. sing. / ²λοιδοριας [loidorias] Gen. sing. ("railing for railing" - λοιδοριαν αντι λοιδοριας [loidorian anti loidorias] Lit: "reviling instead of reviling").