ˌdiˌfrakˈtäməd.ə(r) noun
Etymology: diffract ion + -o- + -meter
: an instrument for measuring the diameters of small particles in a microscope field by means of the diffraction rings which appear to surround them
• dif·frac·to·met·ric di|fraktə|me.trik adjective
• dif·frac·to·met·ri·cal·ly -trə̇k(ə)lē adverb