An electrolyte solution, whose constituents are not electroactive in the range of
applied potentials being studied, and whose
ionic strength (and, therefore, contribution to the conductivity) is usually much larger than the
concentration of an
electroactive substance to be dissolved in it.
Source:
PAC, 1985, 57, 1491
(Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations
1985))
on page 1501