Fastened or tied something to something else, or got married (married couple 'hitched' together).
From Old English and Germanic roots meaning 'to fasten or tie,' used for centuries to describe physical fastening. By the 1800s, it became slang for getting married, as the idea of two people being 'hitched together' paralleled the fastening of objects.
The word 'hitched' for marriage probably began as humorous or working-class slang—it treated marriage like you'd hitch a horse to a wagon—but it stuck around and became so normal that people forget the metaphor originally compared spouses to livestock being tied together.
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