The definition of a singletree is a bar between the pulling animal and the wagon or plow that balances the weight being pulled.
An example of a singletree is a metal crossbar between a horse and a buggy.
a wooden bar swung at the center from a hitch on a plow, wagon, etc. and hooked at either end to the traces of a horse's harness
Origin of singletreealtered (as if ; from single) ; from swingletree ; from Middle English swingle, rod, whip + tre, tree
Origin of singletreeAlteration (influenced by doubletree) of swingletree.