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.
PAC, 1985, 57, 1491
(Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985))
on page 1501
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook