וַיְקֹנֵ֥ן הַמֶּ֛לֶךְ אֶל־אַבְנֵ֖ר וַיֹּאמַ֑ר הַכְּמ֥וֹת נָבָ֖ל יָמ֥וּת אַבְנֵֽר׃
And the king lamented for Abner, and said: Should Abner die as a churl dieth?
Rashi on II Samuel
The death of someone wicked. Like the death by sword of a wicked person.