(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.

plural of transitive set

(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.

plural of breakfast set

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

plural of set theory

Third-person singular simple present indicative form of pre-set

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

present participle of set aback

Third-person singular simple present indicative form of set aback