axletree

English

From Middle English axiltre; equivalent to axle +‎ tree. Cognate with Icelandic öxultré.

axletree (plural axletrees)

A bar or beam of wood or iron, connecting the opposite wheels of a carriage, on the ends of which the wheels revolve.
Synonym: axlerod
A spindle or axle of a wheel.
A stimulus or driving force.
- 1831, L[etitia] E[lizabeth] L[andon], chapter X, in Romance and Reality. […], volume I, London: Henry Colburn and Richard Bentley, […], →OCLC, page 80:
  Soon after his arrival, that patent axletree of action, the not knowing what to do with himself, domesticated him during some weeks of the shooting season at Sillery House...

A rod connecting the opposite wheels of a carriage