Most understand that this saying means that the results of an endeavour are paramount. Although we grok this intuitively, it only makes sense when we realise that this literally meaningless saying is a truncation of a perfectly good one: "The proof of the pudding is in the eating".

The source of the unabridged turn of phrase is variously attributed to:

• 1615 Miguel de Cervantes Saavedra auth Don Quixote part 2 chapter 24: "The proof of the pudding is in the eating"
• 1682 Bileau auth Le Lutrin, which read, "The proof of th' pudding's seen i' the eating."

There is currently no English word to describe a phrase that has lost words and become literally meaningless, yet still retain its semantic load, and remain in common use.