Nullity

Nullity may refer to:


 * Legal nullity, something without legal significance
 * Nullity (conflict), a legal declaration that no marriage had ever come into being

Mathematics

 * Nullity (linear algebra), the dimension of the kernel of a mathematical operator or null space of a matrix
 * Nullity (graph theory), the nullity of the adjacency matrix of a graph
 * Nullity, the difference between the size and rank of a subset in a matroid
 * Nullity, a concept in transreal arithmetic denoted by Φ, or similarly in wheel theory denoted by ⊥.