Definition of pessimum in US English:

pessimum

noun

  • The worst or least favourable condition, value, or amount. Opposed to optimum.

adjective

  • Worst, least favourable, especially under a particular set of circumstances.

Origin

Early 19th century. From classical Latin pessimum lowest quality, worst condition, greatest detriment, use as noun of neuter of pessimus worst from the same base as pēior worse + -imus, extended form of suffix forming superlatives. Compare German Pessimum, noun.

Pronunciation

pessimum

/ˈpɛsɪməm/