Difference in the volume or mass of titrant, or the corresponding difference in the volume or mass of titrand, between the end-point value and
equivalence-point value.
Source:
PAC, 2025, 97, 137. 'Glossary of terms for mass and volume in analytical chemistry (IUPAC Recommendations 2024)' on page 3 (https://doi.org/10.1515/pac-2023-0903)