Fessenden, Reginald AubreyPronunciation: /ˈfɛs(ə)nd(ə)n/Definition of Fessenden, Reginald Aubrey (1866–1932), Canadian-born American pioneer of radio-telephony, who invented the heterodyne receiver. Fessenden, Reginald Aubrey in other Oxford dictionaries Definition of Fessenden, Reginald Aubrey in the US English dictionary