1 often foll by: with to distinguish or be distinguished by comparison of unlike or opposite qualities
2 distinction or emphasis of difference by comparison of opposite or dissimilar things, qualities, etc. (esp. in the phrases by contrast, in contrast to or with)
3 a person or thing showing notable differences when compared with another
4 (in painting) the effect of the juxtaposition of different colours, tones, etc.
a (of a photographic emulsion) the degree of density measured against exposure used
b the extent to which adjacent areas of an optical image, esp. on a television screen or in a photographic negative or print, differ in brightness
6 (Psychol) the phenomenon that when two different but related stimuli are presented close together in space and/or time they are perceived as being more different than they really are (C16: (n): via French from Italian, from contrastare (vb), from Latin contra- against + stare to stand)
n (Psychol) the change in the appearance of a colour surrounded by another colour; for example, grey looks bluish if surrounded by yellow
n (Med) a radiopaque substance, such as barium sulphate, used to increase the contrast of an image in radiography
n a microscope that makes visible details of colourless transparent objects. It employs a method of illumination such that small differences of refractive index of the materials in the object cause differences of luminous intensity by interference
Dictionnaire anglais Collins English definition-Thesaurus
Ajouter votre entrée dans le Dictionnaire Collaboratif .