Top definition
A parodic scientific law stating that any headline ending in a question mark can safely be answered with "no." Extremely useful in this age of clickbait.
Clickbait: "Did this man cure cancer by spreading dog shit on his face?? The answer will amaze you!!"

Smart guy: "No. If it was true then it wouldn't need the question mark."

Clickbait: "But don't people enjoy suspenseful headlines?? The answer is astounding!!"

Smart guy: "Betteridge's Law." (Keeps scrolling.)
by the Avenger of Lost Souls July 14, 2016
Happy St. Patties Day!