overstimulate Syllabification: (o·ver·stim·u·late)Pronunciation: /ˌōvərˈstimyəˌlāt/Definition of overstimulate verb [with object] stimulate physiologically or mentally to an excessive degree:caffeine produced by coffee trees overstimulates insects that munch their leavesDerivatives overstimulationPronunciation: /ˈōvərˌstimyəˈlāSHən/ noun overstimulate in other Oxford dictionaries Definition of overstimulate in the British & World English dictionary