1. management, operations research the relative probability of any of several alternative outcomes as determined or estimated by a decision maker when the actual outcome of an event or series of events is not known 2. management, operations research the product of the probability of the event taking place, the probability of being exposed to the event, and the probability of certain outcomes if exposure to the event occurs 3. entomology, pathology the probability that an insect population or outbreak will occur in a particular stand, watershed, or forest, or that a particular tree will be severely damaged under a given set of conditions; e.g., with bark beetles, risk is the short-term expectation of tree mortality in a stand as a result of a bark beetle infestation —note risk is not related to the extent of damage —see hazard 4. the probability that a tree will die within a specified time period 5. fire —see fire risk, hazard, uncertainty This definition last updated 08/15/2008