optimum UK /ˈɒptɪməm/US /ˈɑptɪməm/noun 2adjective 1forms 2 noun2 •The best or most favorable condition, or the greatest amount or degree possible under specific sets of comparable circumstances. •Any long period of time marked by a persistently warm climate; a climatic optimum. adjective1 •The best or most advantageous; surpassing all others.optimum conditions for climbing formsoptima · optimums
