The definitions below refer to Adaptation to Climate Change.
The RESIN project  gives the following definition:
Other International Definitions
In terms of climate change, the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report changes from a vulnerability based framework to a risk based framework. Risk, for the IPCC, is a function of the climate hazard, Exposure and Vulnerability.
- Mach, K.J., S. Planton and C. von Stechow (eds.). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Annex II: Glossary. [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, pp. 117-130.