Emily Dickinson Lexicon

CON'SO-NANCE, n. [Fr. from L. consonantia, consonans, from consono, to sound together; con and sono, to sound. See Sound and Tone.]

1. Accord or agreement of sounds. In music, consonance is an accord of sounds which produces an agreeable sensation in the ear, as the third, fifth and eighth. It denotes also the according intervals. When the interval of a consonance is invariable, it is called perfect; but when it may be either major or minor, it is termed imperfect. – Busby.
2. Agreement; accord; congruity; consistency; agreeableness; suitableness; as, the consonance of opinions among judges; the consonance of a ritual to the Scriptures.