leverage

Where it comes from

Leverage ordinarily means influence or advantage used to achieve a result; originally mechanical advantage from a lever. Leverage was formed in English from lever plus -age. Lever came through Anglo-French levier from lever, to raise, ultimately from Latin levare, to raise or lighten, and levis, light in weight. Leverage first named the action or mechanical advantage of a lever: a small input can move a larger load.

How the meaning developed

That imbalance became a metaphor for strategic influence, then a financial term for using borrowed funds to control a larger investment and magnify both gains and losses.