permeare

Permeare is a verb found in Latin and in Italian as permeare. In Latin it means to pass through, penetrate, or saturate. In Italian and other Romance languages it retains a similar sense of diffusion or infiltration. The term has given rise to English derivatives such as permeate, permeation, and permeable, and to Romance-language forms such as Portuguese permear. The concept is used in both literal and figurative contexts to describe something that spreads through or into another substance or area.

In scientific contexts, permeate describes the movement of a substance through a porous barrier or membrane, driven by concentration gradients or pressure differences. Related terms include permeability (the property of allowing passage), permeation (the process), and permeable (adjective describing a material that allows passage). In everyday usage, a smell, light, or influence can permeate a space or culture. The idea also appears in fields such as chemistry, biology, geology, and material science, where it is contrasted with impermeability to denote varying ease of passage through barriers.