megaphone UK /ˈmɛɡ.əˌfəʊn/US /ˈmɛɡəˌfoʊn/noun 3verb 1forms 3 noun3 •A portable, usually hand-held, funnel-shaped device that is used to amplify a person’s natural voice toward a targeted direction. •(figurative) Mouthpiece or promoter; one who speaks for or publicizes on behalf of another.If Pack does become head of the BBG, critics fear that he will turn Voice of America and the other BBG networks into a megaphone for Trump. — 2018 •A cytotoxic neolignan obtained from the laurel Aniba megaphylla. verb1 •To use a megaphone; to speak through a megaphone. formsmegaphoned · megaphoning · megaphones