ratio decidendi

(law) The legal principle or rationale on which a judicial decision is based.

Japanese Meaning

裁判所の判決を支える法的根拠（裁判判断の根拠となる法原則） / 判決における理由、すなわち判決の論拠

The appellate judge carefully distinguished the obiter dicta from the ratio decidendi before issuing the ruling.

控訴裁判官は判決を下す前に、付随的所見と判決の法理を慎重に区別した。

Sense（1）

(law) The legal principle or rationale on which a judicial decision is based.

rationes decidendi

（ plural ）