gallows-tree gal·lowst·ree uncommon noun 1. instrument of execution consisting of a wooden frame from which condemned persons are executed by hanging Synonymsgallowsgallows treegibbetgallous 2. instrument of execution consisting of a wooden frame from which condemned persons are executed by hanging Synonymsgallowsgallows treegallows-treegibbetgallous Related words Word family gibbet Broader terms instrument of execution Part of hangman's rope WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.