theory

From Wiktionary
theory is on the Academic Word List.

Pronunciation[change]

  • (UK) IPA (key): /ˈθɪəri/ or /ˈθiːəri/ or /ˈθɪri/
  • (US) IPA (key): /ˈθiːəri/ or /ˈθɪri/
  • (file)

Noun[change]

Singular
theory

Plural
theories

Theory is on the Academic Vocabulary List.
  1. (countable) A theory is an idea that tries to explain an observation.
    The new information showed that his theory about growth was incorrect.
    Nobody has disproved Einstein's theory of general relativity.