What's the noun for concordantial? Here's the word you're looking for.
concord
A state of agreement; harmony; union.
(obsolete) Agreement by stipulation; compact; covenant; treaty or league
(grammar) Agreement of words with one another, in gender, number, person or case.
(law, obsolete) An agreement between the parties to a fine of land in reference to the manner in which it should pass, being an acknowledgment that the land in question belonged to the complainant. See fine.
(chord) An agreeable combination of tones simultaneously heard; a consonant chord; consonance; harmony.
“Of course, as one might imagine, the answers elicited proved not to be in unanimous concord.”
“It will be a government that will work by cohesion, concord and peace.”
“It would appear that there was concord between the views of Sir Wilfrid Esdaile concerning his friend and those of Lady Rosa Chumleigh concerning her daughter.”
An alphabetical verbal index showing the places in the text of a book where each principal word may be found, with its immediate context in each place.
(computational linguistics) A list of occurrences of a word or phrase from a corpus, with the immediate context.
“Of course, as one might imagine, the answers elicited proved not to be in unanimous concord.”
“It will be a government that will work by cohesion, concord and peace.”
“It would appear that there was concord between the views of Sir Wilfrid Esdaile concerning his friend and those of Lady Rosa Chumleigh concerning her daughter.”
concordancer
A person or automated system that compiles a concordance.