He pored over his notes the night before the exam. My friend recommended a facial that minimizes pores. Pore over the map before you leave for your trip. Pieces of food keep getting caught in the sponge's pores.

Examples from Collins dictionaries Moisture inside the mold evaporated during the casting and the resulting metal had an unacceptable level of porosity. As moisture transport is closely related to the formation of pores, the more water lost during cooling, the higher the porosity achieved.

Weakness and vulnerability. (Definition of porous from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)

If something is full of tiny holes or openings, you can describe it as porous. A sponge is porous, and if the border between countries is open for anyone to cross easily, it too can be called porous. You can see the word pore — meaning "a tiny opening" — in porous.