plural of viral envelope

plural of work envelope

plural of convex envelope

(mathematical analysis, of a set) Convex hull.

plural of concave envelope

(mathematics, optimisation theory, of a function on a set) For a given set S⊆ℝⁿ and real-valued function f defined on the convex hull conv(S), the lowest-valued concave function that overestimates or equals f over S.

plural of padded envelope

A large thick envelope, now usually coated with foam or bubblewrap, used to protect fragile items in the mail.

(US) An envelope whose mailing for an authorized purpose does not requiring postage, while its unauthorized use may be penalized.

An airmail envelope with a distinct pattern of spaced diamonds in alternating red and blue colours around the outer edge.