Lowest amount of a substance that, when introduced into the body, may cause death to individual species of test animals under a defined set of conditions.
Source:
PAC, 1993, 65, 2003. 'Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)' on page 2071 (https://doi.org/10.1351/pac199365092003)