Blau

Etymology
From the adjective.

Noun

 * 1)  the colour blue (as a whole)
 * 2)  a particular tone of blue
 * 3)  azure; blue in heraldry
 * 4)  a vast blue area, especially:
 * 5) the sky
 * 6) the sea
 * 1) the sea

Etymology
From the adjective.

Noun

 * 1) blue