most favorable condition or greatest degree or amount possible under given circumstances most desirable possible under a restriction expressed or implied; 'an optimum return on capital'; 'optimal concentration of a drug'.
The level of an abiotic factor or condition in the environment within the tolerance range at which a species or population can function most efficiently or with the greatest positive effect to its physiological or reproductive fitness.
The 'optimum' attitude mode for the Microlab-1 spacecraft refers to the periods of time when the plane of its orbit is face-on to the sun This is optimum with regard to power, since the solar panels can continuously face the sun It's not optimal with resp
