Permeal

Permeal is a neologism that does not have a single, widely accepted definition in mainstream reference works. In informal and speculative contexts, the term is used to describe concepts related to permeability, often as a blend of permeable and the suffix -al. Because its meaning varies by domain and author, there is no standardized definition for permeal.

In materials science and engineering discussions, permeal is sometimes used to denote a hypothetical or proposed class of materials that exhibit selective diffusion. Such a use emphasizes controlled permeation, where certain molecules pass through a barrier while others are held back. In food science and packaging, permeal can refer to semi-permeable films or coatings designed to manage moisture, aroma, or flavor release, balancing protection with controlled interaction with the environment.

Because permeal is not standardized, it may appear in fictional, design-oriented, or speculative writings as well as in informal technical discourse. There is little to no formal definition in major encyclopedias or specialized glossaries, and usage tends to vary between practitioners and writers. For related ideas, see permeability, semi-permeable membranes, and edible films.