| Subject | English | German |
| el. | principal mode | L-Mode |
| commun. | principal mode | Grundschwingungsart (microwave) |
| commun. | principal mode | Hauptmode (microwave) |
| el. | principal mode | TEM-Mode |
| phys. | principal mode | Grundmode (e.g. of the waveguide) |
| gen. | principal modes of vibration | Hauptschwingungsformen |