Prodigal describes wasteful, extravagant spending, or someone who left and later returned, as in the phrase "prodigal son." Prodigious describes something remarkably large, powerful, or impressive, such as a prodigious talent. The two look alike but come from different Latin roots and mean quite different things.
The core difference
Prodigal means wastefully extravagant, while prodigious means remarkably large or impressive in size or degree.
- prodigal — spending money or resources wastefully and extravagantly: His prodigal spending left him broke within a year.
- prodigious — remarkably large, powerful, or impressive in size or degree: She has a prodigious talent for languages.
How to tell them apart
People often assume "prodigal" means impressive or exceptional, likely because it sounds like "prodigy" and "prodigious." In fact, prodigal is about waste and extravagance, most famously in the biblical Parable of the Prodigal Son, where the word describes a son who squandered his inheritance before returning home.
Prodigious, meanwhile, is the word that pairs with talent, achievement, and scale — a prodigious memory, a prodigious effort. A useful check: if the sentence is really about squandering money or resources, or about someone returning after a reckless departure, reach for prodigal; if it is about something impressively large or skilled, reach for prodigious.
