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The expression “as keen as mustard” originates from 17th-century England and is used to describe someone who is eager, enthusiastic, or very keen.
Origins of the Phrase:
1. Early Usage in 1670s:
• The phrase is believed to have first appeared in Thomas Shadwell’s 1671 play The Rehearsal.
• It described someone who was excitable and enthusiastic—traits associated with the sharp, spicy flavor of mustard.
2. Mustard’s Popularity in English Cuisine:
• Mustard was a highly popular condiment in England at the time, known for its sharp and strong flavor.
• Its pungency likely inspired the metaphor for someone who was sharp-witted, eager, or ready for action.
3. Connection to Prepared Mustard:
• In the 17th century, prepared mustard became widely available and was often described as “ready-made”—a term also associated with someone being ready and prepared for any situation.
4. Literary Evolution:
• Over time, the expression evolved to describe not just sharpness but enthusiasm and energy, reflecting the zestful nature of mustard.
Modern Usage:
• The phrase is still used today to mean someone is extremely eager or enthusiastic about something.
• Example: “He’s as keen as mustard to get started on the new project.”
So, the “keen as mustard” expression draws from mustard’s sharp flavor, symbolizing energy, enthusiasm, and readiness in human behavior.