穴 - hole, aperture, slit

air hole; windhole; air vent

hole; opening; orifice; perforation

cave; cavern; den; grotto

filling (up) a hole

pitfall; trap; pit

grave (pit)

bucket; pail

to have a narrow view of things; to peek at the sky through the eye of a needle

Japanese mud shrimp (Upogebia major)

anus; asshole; arsehole

fill-in-the-blank question; cloze test (i.e. text with words removed)

cave from which cold wind blows