The use of this term is discouraged, and the term applied potential should be used instead, for non-periodic signals. However, it is retained here for sinusoidal and other periodic signals because no suitable substitute for it has been proposed.
Source:
PAC, 1985, 57, 1491. 'Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)' on page 1505 (https://doi.org/10.1351/pac198557101491)