To give something as security for a loan (to pawn), or to hamstring an animal by cutting the tendons in the hock (back leg joint).
From Dutch 'hok' (a pawn shop or prison), or from Old Norse 'hoxin' (to hamstring). The pawn shop meaning entered English around the 1600s during Dutch trading prominence. The livestock meaning is older, dating to farming practices for controlling animals.
In hard economic times, people historically would 'hock' their valuables—everything from jewelry to clothing to furniture—at pawn shops for immediate cash. This created the stereotypical image of pawn shops as places where the desperate went, but pawn shops were actually the credit system for people without access to banks.
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