Probability expressed as a percentage is a value between 0% and 100%. If there is a 0% probability that something happens, then the thing is impossible. If there is 100% probability that something happens, then the thing is definite. This uses words to describe a number.
Now turn it around. What probability do you use to describe the words? If something is unlikely, what are the chances that something occurs? Adam Kucharski made a quiz that lets you assign probability to common words used to express probability. Then compare against what others answered.
See also: the distributions of likelihood and the CIA rendition from the 1990s.
