As a Noun: 1. In mathematics, the extent to which an event is likely to occcur, measured by the ratio of the favourable cases to the whole number of cases possible. English = probability. As Modifier: 1. Used to indicate that something is possible or may be true, but you are not certain; to indicate that you are making a rough guess at a number or quantity, rather than stating it exactly. English = perhaps, maybe. 2. Used to link a number of alternatives, to give another alternative, or to introduce a comment which corrects or modifies something you have just said. English = or. 3. Used immediately next to a verb to mean it is possible that what you say is true, but you are not certain. English = may, might.