pore

(noun) any tiny hole admitting passage of a liquid (fluid or gas).

(noun) any small opening in the skin or outer surface of an animal.

(noun) a minute epidermal pore in a leaf or stem through which gases and water vapor can pass. Synonyms: stoma, stomate.

(verb) direct one's attention on something. Synonyms: concentrate, focus, center, centre, rivet. Example: "Please focus on your studies and not on your hobbies."