optimum vs. optimal

optimum vs. optimal: 's the difference?

Optimum and optimal are synonyms when they function as adjectives meaning “best,” as in We created it under optimal/optimum conditions. Less frequently, optimum can function as a noun, as in This machine has reached its optimum, while optimal only ever functions as an adjective.

optimum

noun

plural optima optimums.
  1. the best or most favorable point, degree, amount, etc., as of temperature, light, and moisture for the growth or reproduction of an organism.
  2. the greatest degree or best result obtained or obtainable under specific conditions.

adjective

  1. most favorable or desirable; best:

    optimum conditions.

    Synonyms: , ,

optimal