Meaning of PROBABILITY in English
Medicine is to a significant degree based on probability theory. Probability in this context is the likelihood of something happening. The abbreviation for probability is P. For example, P<0.05 indicates that the probability of something occurring by chance alone is less than 5 in 100, or 5%. As a matter of fact, P<0.05 is usually taken as the level of biologic significance where a result may be considered meaningful.
English dictionary of medicine. Английский словарь медицины. 2012