Nonpermeable
Part of speech: adjective
Definition: not permeable 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
Part of speech: adjective
Definition: impossible to permeatenot allowing passage, especially of liquids; waterproof