Precautionary principle
Definition
Is defined in the Preamble to the Convention on Biological Diversity (1992): "[W]here there is a threat of significant reduction or loss of biological diversity, lack of full scientific certainty should not be used as a reason for postponing measures to avoid or minimize such a threat."
Source
Appendix B Glossary. "Climate, Community & Biodiversity Standards". (Second Edition - December 2008). http://www.cbd.int/convention/convention.shtml
Alternative definition
The axiom that "a lack of full scientific certainty shall not be used as a reason for postponing cost effective measures to prevent environmental degradation".
Alternative source
Fisheries and Aquaculture Department, FAO, 2014;