Aesculus aes·cu·lus uncommon noun 1. deciduous trees or some shrubs of North America; southeastern Europe; eastern Asia Synonymsgenus Aesculus Related words Word family Aesculus hippocastanum Broader terms dicot genus Parts Hippocastanaceae Part of horse chestnut WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.