Permeants

Part of speech: noun

Definitions

1. Substances capable of passing through or penetrating a membrane or barrier ; agents that diffuse or spread throughout a medium or material ; compounds that allow or facilitate the movement across permeable surfaces
2. Materials that move through membranes by diffusion or osmosis ; chemical entities that infiltrate barriers or structural layers ; particles that traverse permeable environments or tissues
3. Elements or molecules that pass across cellular or material boundaries ; substances that penetrate porous or semipermeable layers ; agents that migrate through membranes or filters in biological or chemical processes

Etymology: "Permeants" is the plural of "permeant", a noun formed from "permeate" and the suffix "-ant". The suffix is English in its modern shape, descended through Latin "-ans" and Old French "-ant" from a Proto-Indo-European ending that marked a present participle, so the word is essentially a verb with an agent ending bolted on. Its meaning follows the verb: to permeate is to pass through or fill a space throughout, so a permeant is whatever does that job. The plural form matters because the noun is used for classes of substances rather than single things. Chemists and biologists speak of permeants when they compare how different molecules cross a membrane, and the word names the thing doing the crossing rather than the barrier it crosses. The same sense of agent applies to the broader meaning of anything that spreads through a medium.

Synonyms: penetrants, diffusants

Antonyms: barriers, impermeables