This refers to a specific type of crossword clue where the answer is a word or phrase related to leanness or lack of fat. A typical clue might be “Lean Jack” with the answer being “SPRAT.” This relies on the familiar nursery rhyme/folk song “Jack Sprat could eat no fat, his wife could eat no lean.” The clue uses “Jack” and the concept of no fat to evoke this association in the solver’s mind.
Such clues demonstrate how crossword puzzles can draw upon diverse cultural knowledge, from literature and music to history and everyday expressions. They require solvers to think laterally and make connections between seemingly disparate concepts. This type of clue can range in difficulty depending on the obscurity of the reference and the complexity of the wordplay involved. The “Jack Sprat” rhyme itself has historical roots, appearing in various forms over centuries, adding a layer of cultural significance to its use in crossword puzzles.