Definition of optimum in US English:



  • Most conducive to a favorable outcome; best.

    ‘the optimum childbearing age’
    • ‘It's going to take at least six to eight months under optimum conditions to grow another stem cell.’
    • ‘Choose a plot that receives optimum sunshine and avoid steep slopes.’
    • ‘The state's role is to gently guide the actions of each individual, so that the optimum outcome for all is reached and sustained.’
    • ‘He admits he was not in optimum shape last season, and his performances suffered as a result.’
    • ‘Visit the bookshop or fill out a questionnaire to see what supplements you need to keep yourself in optimum condition.’
    • ‘A customer can be confident that the bottle taken from the retailer's shelf will be at optimum maturity.’
    • ‘When they attacked him, he made optimum use of his energies and floored them all.’
    • ‘The single will be launched on The Late Late Show with the hope of reaching optimum sales in Christmas week.’
    • ‘So why are some of those who manage to provide this optimum environment for their children now demanding to be compensated?’
    • ‘Attention should be placed on the correct type of computer furniture and also optimum lighting.’
    • ‘So it is irrelevant what he or she thinks is a fair, just, or optimum law or philosophy of life.’
    • ‘All his businesses are run to deliver optimum value and performance to shareholder and customers.’
    • ‘After slaughter, it ought to have been hung for approximately 28 days for optimum texture and flavour.’
    • ‘The garden has a water feature, paving and decking as well as plants that provide optimum scents.’
    • ‘There is a body of evidence that only custom fitted suits give optimum performance.’
    • ‘So did you find that there was any sort of optimum age for starting school?’
    • ‘Positioning oneself for optimum tanning on a Balearic beach requires some thought.’
    • ‘Physically he looks really well - his coat is black and glossy and he's probably about optimum weight.’
    • ‘At Macy's age, the optimum amount of alcohol for her to consume is less than one unit a day.’
    • ‘It avoids wasting lime and fertiliser, which in turn leads to optimum yields.’
    best, most favourable, most advantageous, most appropriate, ideal, perfect, prime, optimal, model
    View synonyms


  • The most favorable conditions or level for growth, reproduction, or success.

    • ‘To avoid issues regarding bad convergence and local optima all analyses were run from multiple starting values and results were accepted only when several starting points converged on the same maximum likelihood.’
    • ‘If habitat optima differ between the sexes, breeding habitat may reflect more the optimum of the controlling sex (presumably the choosing females) than that of the noncontrolling sex, entailing a cost to the latter.’
    • ‘For some, but not all, of these thermally sensitive traits acclimatization leads to adaptive shifts in thermal optima and limits.’
    • ‘If the absolute value of a genetic correlation is less than 1, selection will eventually bring trait means to their respective individual optima, although it may require an extremely long time.’
    • ‘As Raup observed, these peaks need not be adaptive optima for each individual trait but rather may be best interpreted as compromise solutions that satisfy several functional constraints.’
    peak, pinnacle, zenith, highest point, high point, crown, crest, summit, top, tip, apex, apogee
    View synonyms


Late 19th century: from Latin, neuter (used as a noun) of optimus ‘best’.