A fishing net that is used by securing it to a fixed underwater framework.

To fish using a set net.

(mathematics) The underlying set of mathematical structures such as posets and matroids.

(combinatorics) A subset of a group such that any element of the group can be expressed as the difference (or the quotient) of two elements in such subset.

(set theory) Any set X such that for any x ∈ X, if y ∈ x then y ∈ X; equivalently, such that if x ∈ X and x is not an urelement then x ⊆ X.

The china or other ware used for serving and eating breakfast.

plural of set theory

(transitive) To startle or shock; to render (someone) confused or disconcerted.

present participle of set aback

To begin a chase or hunt for (someone or something).