ACHROMATIZE is a 11 letter word that starts with A.
\A*chro"ma*tize\, v. t. [imp. & p. p. {Achromatized}; p. pr. & vb. n. {Achromatizing}.] [Gr. 'a priv. + ? color.] To deprive of color; to make achromatic.
WordNet Dictionary