- For two periodic quantities with the same frequency, the lag in phase of one respective to the other. Expressed in radians or degrees. Also called angle of lag, or lag angle.
- In the transmission of a single-frequency wave from one point to another through a transmission line or system, the time interval between the instants at which a given point of a wave passes through two specified points of said transmission medium.
- synonymphase difference
- synonymphase displacement
- synonymphase lag