Cut the Mustard

Recorded from the early 20th century, with an early confirmed use by the American writer O. Henry in 1907: "I looked around and found a proposition that exactly cut the mustard." Where the specific wording comes from is genuinely unresolved. One theory suggests it's a corrupted form of the military phrase "cut the muster," but nobody has ever found an actual example of "cut the muster" being used, which rather undermines the theory. Another points to mustard's older figurative use as a symbol of sharpness, zest, and enthusiasm, as in the much older phrase "keen as mustard," recorded from the late 1600s. A literal theory involving harvesting mustard plants has also been floated, again without supporting evidence. All of it remains guesswork.