Summum bonum is a Latin expression meaning the highest or ultimate good, which was introduced by the Roman philosopher Cicero to denote the fundamental principle on which some system of ethics is based — that is, the aim of actions, which, if consistently pursued, will lead to the best possible life.

What language is Bonum?

Slave!, Ave! or Bonum mane = good morning in Latin language.

What means summum bonum?

: the supreme good from which all others are derived.