nonporous

The word is a modern English compound formed by directly combining the negative Latin prefix "non-" with the adjective "porous." "Porous" itself descends from the Latin porus, a borrowing from the Greek poros, which originally meant a passage, ford, or channel. This concrete sense of a physical passageway narrowed in scientific Latin to refer specifically to the tiny interstices in a rock or membrane. By adding the prefix "non-," the word logically inverts the property, creating a term that precisely describes a material lacking these minute passages, thus incapable of permeation by fluids or gases.

Structure: non (not) + porous (having pores) - non: A prefix of Latin origin, meaning "not." It functions as a negative or privative element. - porous: An adjective of Latin and Greek origin (from Latin porus "pore," from Greek poros "passage, pore"), meaning "having pores." It functions as the core descriptive element.