countershadingn.

1896 Auk Apr. 127 The dark collars of the males of most species of Duck are absolute countershading to the light from the sky.

1909 A. H. Thayer Concealing-coloration in Animal Kingdom ii. 25 Obliterative Coloration is a phrase that will fit the general principle, and Obliterative or Countershading may be used as a stricter term for the essential root of it.

1923 R. Cortissoz Amer. Artists ii. 36 The countershading of the same model, according to nature, would cause it to melt into the background.

1940 H. B. Cott Adaptive Coloration in Animals i. iii. 36 In countershading we have a system of colouring the exact opposite to that upon which an artist depends when painting a picture.

1958 New Biol. 25 103 This countershading is general in animals which are normally lit by bright light from above.

1964 B. P. Boden & E. M. Kampa in Oceanogr. & Marine Biol. 2 367 These animals..utilize these light organs as a countershading mechanism to erase their silhouette.

1934 Webster's New Internat. Dict. Eng. Lang. Countershade, v.t., in camouflaging, to lighten the local colour of an object in those parts that normally fall into shadow, or, conversely, to darken the parts normally illuminated, thus making the object less conspicuous.

1953 N. Tinbergen Herring Gull's World ii. 14 The young are beautifully countershaded, that is, they are light underneath, which tends to counteract the effect of shadow.