Origin: 1570–80; < Latinignōrāmus we ignore (1st person plural present indicative of ignōrāre to be ignorant of, ignore); hence name of an ignorant lawyer in the play Ignoramus (1615) by the English playwright G. Ruggle, whence current sense
[C16: from legal Latin, literally: we have no knowledge of, from Latin ignōrāre to be ignorant of; see ignore; modern usage originated from the use of Ignoramus as the name of an unlettered lawyer in a play by G. Ruggle, 17th-century English dramatist]
1577, Anglo-Fr. legal term, from L. ignoramus "we do not know," first person present indicative of ignorare "not to know" (see ignorant). The legal term was one a grand jury could write on a bill when it considered the prosecution's evidence insufficient. Sense of "ignorant
person" came from the title role of George Ruggle's 1615 play satirizing the ignorance of common lawyers.