Definition of ratio decidendi in English:

ratio decidendi

Syllabification: ra·ti·o de·ci·den·di
Pronunciation: /ˌrāSHēō ˌdesəˈdendī, ˌrätēō ˌdesəˈdendē

noun (plural rationes decidendi /ˌrätēˈōnēz/)

The rule of law on which a judicial decision is based.
More example sentences
  • Courts are bound by principles of law, the ratio decidendi of cases.
  • The former are described as being the ratio decidendi (reasons for the decision).
  • If property suddenly became available all over the country many of the rationes decidendi of the past would be quite inappropriate.


Latin, literally 'reason for deciding'.

Definition of ratio decidendi in: