'Summum bonum' definitions:

Definition of 'summum bonum'

(from WordNet)
noun
The supreme good in which all moral values are included or from which they are derived

Definition of 'Summum bonum'

From: GCIDE
  • Summum bonum \Sum"mum bo"num\ [L.] (Philos.) The supreme or highest good, -- referring to the object of human life. [Webster 1913 Suppl.]