̷ ̷ˈträməd.ə(r), -mətə- noun
Etymology: International Scientific Vocabulary spectro- + -meter
1. : an instrument used in determining the index of refraction by measuring the external angle of a prism of a substance and also its angle of minimum deviation for light of a given kind
2. : a spectroscope fitted for measurements of the spectra observed with it — compare mass spectrometer