from im- + morigerous (obedient, submissive)
1623 - The English Dictionarie, or an Interpreter of Hard English Words, Henry Cockeram;
"Immorigerous, rude, vnciuill"
From: The Great Exemplar of Sanctity and Holy Life, (1649)
By Jeremy Taylor
Volume II. 1845
Discourse X. A Discourse upon that part of the Decalogue which the Holy Jesus adopted into the institution and obligation of Christianity