The outer surface of a piece of flint.
The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue.
The outer layer of an internal organ or body structure, such as the kidney or the brain.
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.