2 definitions found

From WordNet (r) 2.0 [wn]:

achromatic

adjective

1: being of the achromatic color of maximum lightness; having little or no hue owing to reflection of almost all incident light; "as white as fresh snow"; "a bride's white dress" [syn: {white}] [ant: {black}]

2: being of the achromatic color of maximum darkness; having little or no hue owing to absorption of almost all incident light; "black leather jackets"; "as black as coal"; "rich black soil" [syn: {black}] [ant: {white}]

3: having no hue [ant: {chromatic}]

From The Collaborative International Dictionary of English v.0.44 [gcide]:

Achromatic \Ach'ro*mat"ic\, adjective [Gr. ? colorless; 'a priv. + ?, ?, color: cf. F. achromatique.]

1. (Opt.) Free from color; transmitting light without decomposing it into its primary colors.

2. (Biol.) Uncolored; not absorbing color from a fluid; -- said of tissue.

{Achromatic lens} (Opt.), a lens composed usually of two separate lenses, a convex and concave, of substances having different refractive and dispersive powers, as crown and flint glass, with the curvatures so adjusted that the chromatic aberration produced by the one is corrected by other, and light emerges from the compound lens undecomposed.

{Achromatic prism}. See {Prism}.

{Achromatic telescope}, or {microscope}, one in which the chromatic aberration is corrected, usually by means of a compound or achromatic object glass, and which gives images free from extraneous color.
  Definitions retrieved from local copies of the freely distributed DICT client/server software and databases. Click here for database copyright information. - KM.