ig·no·ra·mus / ˌignəˈrāməs; -ˈraməs/ • n. (pl. -mus·es) an ignorant or stupid person.ORIGIN: late 16th cent.: 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.

ignoramus †endorsement made formerly by a grand jury on a bill returned as not a true bill XVI; ignorant person XVII. — L. ‘we do not know’, in legal use ‘we take no notice (of it)’, 1st pers. pl. pres. ind. of ignorāre IGNORE.