Definition of "shading" [shad•ing]

• A screening against light or heat. (noun)
• The lines or other marks used to fill in outlines of a sketch, engraving, or painting to represent gradations of color or darkness. (noun)
• A small variation, gradation, or difference. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "I say, and Brianna stills, the sneer on her face slipping, her expression shading into something different, something fearful and lost."
• "Double bad, since the shading is all over the place."
• "The shading is done by pen work instead of screentones."