Crepidarian

Part of speech: adjective, noun

Definitions

1. A person who makes or repairs shoes ; someone who offers opinions beyond the limits of their own knowledge or skill
2. A cobbler who works with footwear ; a critic who presumes to judge matters outside their competence
3. One who makes or mends footwear ; a commentator who ventures past the bounds of their own expertise

Etymology: The Roman writer Pliny the Elder tells a story about the painter Apelles, who displayed a picture in public. A cobbler noticed that the sandal in the painting had one strap too few, and Apelles quietly fixed it. Encouraged, the cobbler then began criticizing the figure's leg, and Apelles told him that a shoemaker should judge nothing beyond the sandal. That rebuke became the Latin proverb "ne sutor ultra crepidam," still quoted to mean that people should stick to their own field. The Latin "crepida" was a sandal, borrowed from Greek "krepis," and "crepidarius" meant having to do with sandals or the men who made them. English "crepidarian," a rare word for relating to shoemaking, is built directly on that Latin base, so it names the cobbler's trade in the vocabulary of the Roman learned tradition that produced Pliny's anecdote.