That which covers or conceals; a cover; something spread or laid over or wrapped about another.
Action of the verb to cover.
A continuous map onto a topological space X, 𝜋:E→X, such that there exists a discrete space D and for every x∈X an open neighborhood U⊂X, such that 𝜋⁻¹(U)= displaystyle bigsqcup _(d∈D)V_d and 𝜋|_(V_d):V_d→U is a homeomorphism for every d∈D.
Something that wraps around or surrounds something, as a sheath encases its blade.