GRE TOEFL optimum Definition The most favorable or ideal condition or level. Example "This plant grows at its optimum in moist, shaded soil." Sign in to save GRE Quiz → TOEFL Quiz → ← optimistic option → Study tips featuring "optimum" Map Each Word Into a Connected Network Force Contrast Between Two Similar Words Track How TOEFL Words Behave With Others Related words GRE awe GRE smithereens GRE abacus SAT abase GRE abash GRE abate GRE abbreviate GRE abbreviation SAT abdicate SAT abdomen GRE abduct GRE aberrant