By extension any small opening or interstice, especially one of many, or one allowing the passage of a fluid.
A tiny opening in the skin.
to study meticulously; to go over again and again.
to meditate or reflect in a steady way.
Any small aperture or vent for air or other fluid.
A pore or opening used (especially by arthropods and some fish) for respiration.
The blowhole of a whale, dolphin or other similar species.