phenomenon is on the Academic Word List.

Pronunciation

change
singular
plural (phenomena)

Singular
phenomenon

Plural
phenomena or phenomenons

Phenomenon is on the Academic Vocabulary List.
  1. A phenomenon is a fact or event that you can observe (see or hear or sense), especially one that is not fully understood.
    But this explanation is not enough to explain the observed phenomena.
    Football violence is not a particularly new phenomenon, and it isn't only a British problem.
    These scientists study such phenomena as storms and changing climate.
  2. A phenomenon is a person, show, book, etc. that is very popular.
    'N Sync was something of a pop music phenomenon in the late 90s.
    Snakes as pets are not a new phenomenon, but they do seem to be growing more popular.