- The phase of a waveform is the position of any peak or trough compared to the same feature on a second waveform.
- A phase of matter is a physically distinctive form of a substance, such as the solid, liquid, and gaseous phases of ordinary matter. Also sometimes included in this list are more exotic phases such as superfluids.
- Layers of immiscible liquids are called "phases."
- A lunar phase is the appearance of the Moon as viewed from the Earth. Similarly with planetary phases.
- The compositional technique of phasing discovered by composer Steve Reich is while the same part is played on two instruments, one instrument keeps playing in steady tempo, while the other gradually moves ahead until it becomes back in phase (the rhythmic equivalent of cycling through the phase of two waveforms as above).