early 15c., malignour, "one who traduces or defames another," from Old French malignor, agent noun from malignier (see malign (v.)).
Entries linking to maligner
malign v.
"to slander, speak evil of, defame," mid-15c., malignen (originally with against), from Old French malignier "to plot, deceive, pervert" and directly from Late Latin malignare "to do maliciously," from malignus "wicked, bad-natured, mean, unkind" (see malign (adj.)). Related: Maligned; maligning.