/ˈpərmēəbəl/
Adjective
1. Of or relating to substance, substrate, membrane or material that absorbs or allows the passage of fluids. (wiktionary.org)
2. (Of a material or membrane) Allowing liquids or gases to pass through it. (Google Dictionary)
3. Capable of being permeated or passed through, used especially of substances where fluids can penetrate or pass through. (biology-online.org)
4. Allowing fluids or gases to pass or diffuse through. (wordnetweb.princeton.edu)
Word origin: From Late Latin permeabilis “that can be passed through, passable,” from Latin permeare “to pass through, go over,” from per- “through” + meare “to pass.”