pear haw pear·haw uncommon noun 1. erect and almost thornless American hawthorn with somewhat pear-shaped berries Synonymsblackthornpear hawpear hawthornCrataegus calpodendronCrataegus tomentosa Related words Word family pear hawthorn Broader terms hawthorn Parts Crataegus WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.