- Adjective. (optics) Free from color; transmitting light without color-related distortion.
- Adjective. Containing components such as achromatic lenses and prisms, designed to prevent color-related distortion.
- Adjective. (biology) Uncolored; not absorbing color from a fluid; -- said of tissue.
- Adjective. (music) Having only the diatonic notes of the scale; not modified by accidentals.
- Adjective. Being achromatic in subject.