- Today's Word
Permeate
PUR-mee-ayt
Definition
(verb) To spread throughout something; to penetrate and pass through every part of something.
Example
The smell of woodsmoke had permeated the entire cabin by morning, clinging to every curtain, cushion, and piece of clothing inside.
Word Origin
From Latin permeare, meaning “to pass through” — formed from per- (through) + meare (to pass or go). The root meare is relatively rare in English derivatives but also appears in permeability and impermeable. The word entered English in the mid-17th century, initially used in scientific contexts to describe fluids passing through porous materials before broadening into general use.
Fun Fact
The concept of permeation is central to one of the most consequential technologies of the modern world — the cell membrane. Every living cell is enclosed by a selectively permeable membrane that allows certain molecules to pass through freely while blocking others. This selective permeability is what makes life as we know it possible — it allows cells to absorb nutrients, expel waste, and maintain the precise internal chemistry required to function. Scientists studying membrane permeability have unlocked breakthroughs in drug delivery, water filtration, and even carbon capture technology.