probability

UK: /ˌprɒbəˈbɪləti/ | US: /ˌprɑːbəˈbɪləti/

Definition

  1. n. the likelihood of an event occurring, expressed as a ratio or percentage

  2. n. (mathematics) a measure quantifying the chance of a specific outcome in a set of possible outcomes

  3. n. a probable or expected situation or result

Structure
prob <test/prove, from Latin *probare*>ability <capacity, from Latin *-abilitas*>
Etymology

The word probability traces back to Latin probabilitas, derived from probabilis ("provable, credible"), itself from probare ("to test, prove"). The morpheme prob- reflects the concept of testing or verification, while -ability denotes a measurable capacity. Over time, the term evolved from "provability" to its modern focus on quantifying uncertainty, influenced by mathematical theory in the 16th–17th centuries.

Examples

  1. The probability of rain tomorrow is 70%.

  2. In quantum mechanics, probability plays a central role.

  3. There’s a high probability he’ll arrive late.

  4. Statisticians calculate probability using complex models.

  5. The experiment reduced the probability of error to less than 1%.