Cases of word usage

1) allowing air to flow over or around easily (aerodynamic)

2) an imaginary line around which a turning object spins (axis)

3) going a long way around (circuitous)

4) round or curved in shape; moving around (circular)

5) to prepare (land) by ploughing etc; help (crops) to grow (e.g. by breaking up the soil around them) (cultivate)

6) (the region near) an imaginary line around the Earth, or drawn on maps, at an equal distance from the north and south poles (equator)

7) a person more interested in what goes on around her or him than in personal thoughts and feelings (extrovert)

8) a circular band of wood or metal as put around a barrel etc; a large ring with paper stretched over it through which circus rides and animals jump (hoop)

9) to think deeply or dreamily, ignoring what is happening around one (muse)