Definition of achromatize in English:
achromatize
(also achromatise)
verb əˈkrəʊmətʌɪz(ˌ)eɪˈkrəʊmətʌɪz
with object To make (something, especially a lens) achromatic.
Origin
Early 19th century; earliest use found in Encyclopaedia Metropolitana. From achromat- + -ize.