bright line
n.— «“Bright lines,” as in “bright-line rule,” meaning a clear, unambiguous standard, are in demand in other contexts as well.» —“Bright lines and the search for certainty” by Ruth Walker Christian Science Monitor (Boston, Mass.) Dec. 15, 2005. (source: Double-Tongued Dictionary)
Further reading
It was a dark and stormy night. So begins the long and increasingly convoluted prose of Edwards Bulwer-Lytton’s best-known novel. Today the annual Bulwer-Lytton Contest asks contestants for fanciful first sentences that are similarly...
After hearing our conversation about how dictionaries decide on a preferred pronunciation, and specifically about how to pronounce aioli, Vern from San Diego, California, wrote to say that a friend once made fun of him for pronouncing grimace with a...