cardinal virtue
noun
1.
anything considered to be an important or characteristic virtue:
Tenacity is his cardinal virtue.
2.
cardinal virtues,
Ancient Philosophy.
justice, prudence, temperance, and fortitude.
Origin
1300-50;
Middle English
British Dictionary definitions for
cardinal virtues
cardinal virtues
plural noun
1.
the most important moral qualities, traditionally justice, prudence, temperance, and fortitude