ACHROMIC

achromic, achromous

(adjective) having no color

Source: WordNet® 3.1

Adjective

achromic (comparative more achromic, superlative most achromic)

(science) Uncoloured; not pigmented; lacking in colour.

Usage notes

The OED regards this word as obsolete, but modern usage shows a return of this synonym for achromatic in the fields of medicine and chemistry.

Source: Wiktionary

A*chro"mic, a. [Gr. colorless; priv. + color.]

Definition: Free from color; colorless; as, in Physiol. Chem., the achromic point of a starch solution acted upon by an amylolytic enzyme is the point at which it fails to give any color with iodine.

Source: Webster’s Unabridged Dictionary 1913 Edition