bolometer Syllabification: (bo·lom·e·ter)Pronunciation: /bōˈlämitər/Definition of bolometer noun a sensitive electrical instrument for measuring radiant energy. Derivatives bolometricPronunciation: /ˌbōləˈmetrik/ adjective Origin: late 19th century: from Greek bolē 'ray of light' + -meterbolometer in other Oxford dictionaries Definition of bolometer in the British & World English dictionary