chiaroscuro

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The technique of using light and shade in pictorial representation.
• noun The arrangement of light and dark elements in a pictorial work of art.
• noun A woodcut technique in which several blocks are used to print different shades of a color.
• noun A woodcut print made by this technique.

from The Century Dictionary.

• noun Light and shade; specifically, the general distribution of light and shade in a picture, whether painted, drawn, or engraved— that is, the combined effect of all its lights, shadows, and reflections. Strictly speaking, however, every object on which light strikes has its own chiaroscuro.
• noun A drawing in black and white.
• noun A method of printing engravings from several blocks representing lighter and darker shades, used especially in the fifteenth and sixteenth centuries; also, an engraving so printed.
• Of or pertaining to light and shade in painting, drawing, or engraving.
• Also clair-obscure, clare-obscure.
• noun A style of painting on enameled pottery practised by the Italian potters.

from the GNU version of the Collaborative International Dictionary of English.

• noun The arrangement of light and dark parts in a work of art, such as a drawing or painting, whether in monochrome or in color.
• noun The art or practice of so arranging the light and dark parts as to produce a harmonious effect. Cf. clair-obscur.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun art An artistic technique developed during the Renaissance, referring to the use of exaggerated light contrasts in order to create the illusion of volume.
• noun art A monochrome picture made by using several different shades of the same color.
• noun art The use of blocks of wood of different colors in a woodcut.
• noun photography A photographic technique in which one side of a face (for example) is well lit and the other is in shadow.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a monochrome picture made by using several different shades of the same color