Cozeroset
This article defines a property over pairs of a topological space and a subspace, or equivalently, properties over subspace embeddings (viz, subsets) in topological spaces
A subset of a topological space has this property in the space iff its set-theoretic complement in the whole space is a/an: zeroset
Definition
A subset of a topological space is a cozeroset if it is the set-theoretic complement of a zeroset.