aplanatic

• POS: Adjective
• HYPHEN: ap=la=nat=ic

CIDE DICTIONARY

aplanatic, a. [Gr. 'a priv. + disposed to wander, wandering, to wander.].

 Having two or more parts of different curvatures, so combined as to remove spherical aberration; -- said of a lens.  [1913 Webster]

Aplanatic focus of a lens (Opt.), the point or focus from which rays diverging pass the lens without spherical aberration. In certain forms of lenses there are two such foci; and it is by taking advantage of this fact that the best aplanatic object glasses of microscopes are constructed.

OXFORD DICTIONARY

aplanatic, adj. (of a reflecting or refracting surface) free from spherical aberration.

Etymology

Gk aplanetos free from error f. a- not + planao wander

ROGET THESAURUS

aplanatic

Achromatism

N achromatism, decoloration, discoloration, pallor, pallidness, pallidity, paleness, etiolation, neutral tint, monochrome, black and white, uncolored &c (color), colorless, achromatic, aplanatic, etiolate, etiolated, hueless, pale, pallid, palefaced, tallow-faced, faint, dull, cold, muddy, leaden, dun, wan, sallow, dead, dingy, ashy, ashen, ghastly, cadaverous, glassy, lackluster, discolored, light-colored, fair, blond, white, pale as death, pale as ashes, pale as a witch, pale as a ghost, pale as a corpse, white as a corpse.