reflectometer Syllabification: (re·flec·tom·e·ter)Pronunciation: /riˌflekˈtämətər, ˌrē-/Definition of reflectometer noun an instrument for measuring quantities associated with reflection, in particular (also time domain reflectometer) an instrument for locating discontinuities (e.g., faults in electric cables) by detecting and measuring reflected pulses of energy. Derivatives reflectometryPronunciation: /-ˈtämətrē/ noun reflectometer in other Oxford dictionaries Definition of reflectometer in the British & World English dictionary