ˌakrōˌmad.ēˈāsēˌē, -māshē- noun plural
Usage: capitalized
Etymology: New Latin, from Achromatium, type genus (from achromat- + -ium ) + -aceae
: a family usually placed in the order Beggiatoales that includes large motile aquatic bacteria containing sulfur or calcium carbonate inclusions but no photosynthetic pigments