summum bonum

Learned borrowing from Latin summum bonum.

• (Received Pronunciation) IPA^(key): /ˌsʌməm ˈbəʊnəm/, /ˌsʊməm ˈbɒnəm/
• (General American) IPA^(key): /ˌsʊməm ˈbɑnəm/, /ˌsʌməm ˈboʊnəm/

summum bonum (plural summa bona)

1. (philosophy) The greatest good; the ultimate importance; the singular end which human beings ought to pursue.

   Antonym: summum malum

   • 1621, Democritus Junior [pseudonym; Robert Burton], “Democritus Iunior to the Reader”, in The Anatomy of Melancholy, […], Oxford, Oxfordshire: Printed by John Lichfield and Iames Short, for Henry Cripps, →OCLC, page 33:

     In a word, euery man for hiw owne ends: our ſummum bonum is commodity, and the Goddeſſe we adore is Dea moneta, Queene Mony, to whom wee daily offer ſacrifice, which ſteeres our hearts, hands, affections, all: […]

• Summum bonum on Wikipedia.Wikipedia
• Summum Bonum in the Encyclopædia Britannica (11th edition, 1911)

From summus (“superlative of superus”) + bonum (“a moral good”).

summum bonum n (genitive summī bonī); second declension

1. (medieval, philosophy) The highest good; an ultimate goal of human existence.

Second-declension adjective with a second-declension noun (neuter).