Nonpermeable vs. Impermeable

Nonpermeable (adjective)

Not permeable.

Nonpermeable (adjective)

Having the same magnetic permeability as that of free space, so that the material in question has a magnetic permeability mu = mu_0 (where μ₀ = 4π×10⁻⁷ N A⁻² exactly in SI units).

Impermeable (adjective)

Impossible to permeate.

Impermeable (adjective)

Not allowing passage, especially of liquids; waterproof.