Word Study
singletree
CIDE DICTIONARY
singletree, n. [Cf. Swingletree.].
The pivoted or swinging bar to which the traces of a harnessed horse are fixed; a whiffletree. [1913 Webster]
" When two horses draw abreast, a singletree is fixed at each end of another crosspiece, called the doubletree." [1913 Webster]
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