debye Syllabification: (de·bye)Pronunciation: /diˈbī/ (also debye unit)Definition of debye noun Chemistry a unit used to express electric dipole moments of molecules. One debye is equal to 3.336 × 1030 coulomb meter. Origin: early 20th century: named after Debye, Peterdebye in other Oxford dictionaries Definition of debye in the British & World English dictionary