Dictionary

The colour of the clear sky or the deep sea, between green and violet in the visible spectrum, and one of the primary additive colours for transmitted light; the colour obtained by subtracting red and green from white light using magenta and cyan filters; or any colour resembling this.

A blue dye or pigment.

Any of several processes to protect metal against rust.

Blue clothing

Example: The boys in blue marched to the pipers.

(usually in the plural) A feeling of sadness or depression.

Example: I've got the blues today.

A musical form, African-American in origin, generally featuring an eight-bar or twelve-bar blues structure and using the blues scale.

Example: A large portion of modern popular music is influenced by the blues.

A uniform made principally of a blue fabric.

Example: The marched in their dress blues.

Any of a number of sports teams which wear blue kit.

To make or become blue.

To treat the surface of steel so that it is passivated chemically and becomes more resistant to rust.

(laundry) To brighten by treating with blue (laundry aid)

To spend (money) extravagantly; to blow.