late 16th century (as the indorsement made by a grand jury on an indictment considered backed by insufficient evidence to bring before a petty jury): Latin, literally ‘we do not know’ (in legal use ‘we take no notice of it’), from ignorare (see ignore). The modern sense may derive from the name of a character in George Ruggle's Ignoramus (1615), a satirical comedy exposing lawyers' ignorance.