Cases of word usage

1) (something shaped like) the curve of the moon in the first quarter (especially a row of houses) (crescent)

2) a total or partial disappearance of the light of the sun (when the moon is between it and the earth), or of the moon (when the earth's shadow falls on it) (eclipse)

3) a circle of light round the sun or moon (halo)

4) of the moon (lunar)

5) something in which something else is fixed or fastened; a position of an instrument such as 'high' or 'low'; the act of (the Sun, Moon etc) going down (setting)

6) the space we look up to from the earth, where we see the sun, moon and stars (sky)

7) to become less or weaker; (of the moon) to show a decreasing bright area after full moon (wane)