N innocence, guiltlessness, incorruption, impeccability, clean hands, clear conscience, mens sibi conscia recti, innocent, lamb, dove, innocent, not guilty, unguilty, guiltless, faultless, sinless, stainless, bloodless, spotless, clear, immaculate, rectus in curia, unspotted, unblemished, unerring, undefiled, unhardened, Saturnian, Arcadian, inculpable, unculpable, unblamed, unblamable, blameless, unfallen, inerrable, above suspicion, irreproachable, irreprovable, irreprehensible, unexceptionable, unobjectionable, unimpeachable, salvable, venial, harmless, inoffensive, innoxious, innocuous, dove-like, lamb-like, pure, harmless as doves, innocent as a lamb, innocent as the babe unborn, more sinned against than sinning, virtuous, unreproved, unimpeached, unreproached, innocently, with clean hands, with a clear conscience, with a safe conscience, murus aeneus conscientia sana.

For further exploring for "sinless" in Webster Dictionary Online