noun.
The act of discoloring, or the state of being discolored; alteration of color.
noun.
That which is discolored; a discolored spot; a stain: as, spots and discolorations of the skin.
noun.
Specifically In entomology, an indistinct, paler, or discolored part of a surface; that which is colorless or nearly so, as if faded out.
noun.
Alteration of complexion or of the appearance of things: as, the discoloration of ideas.