Redundance, Redundancy, n.
Etymology: [L. redundantia: cf. F. redondance.]
1. The quality or state of being redundant; superfluity; superabundance; excess.
2. That which is redundant or in excess; anything superfluous or superabundant. Labor . . . throws off redundacies. Addison.
3. (Law)
Surplusage inserted in a pleading which may be rejected by the court without impairing the validity of what remains.
Shades of meaning
Fernald has no entry of its own for redundancy; he lists it under circumlocution, excess.
Where he writes about it:
Etymologically, diffuseness is a scattering, both of words and thought; redundancy is an overflow. — from circumlocution
Redundance or redundancy refers chiefly to literary style, denoting an excess of words or matter. — from excess