"there is no technical difference between lakes and ponds, according to the National Park Service. While the distinction between lakes and ponds can be a bit blurry, there are some general guidelines. For example, if sunlight can reach the bottom of the entire body of water, it's generally considered a pond, according to the National Park Service. Conversely, if the body of water is deep enough in some places that sunlight cannot penetrate it, it's generally considered a lake.
When it comes to size, though, there are no exact guidelines. Ponds are generally smaller than lakes, but there's no universal standard. That means some things we call a pond might be considered a lake by some. And some lakes may be more pond-like to some people."
"there is no technical difference between lakes and ponds, according to the National Park Service. While the distinction between lakes and ponds can be a bit blurry, there are some general guidelines. For example, if sunlight can reach the bottom of the entire body of water, it's generally considered a pond, according to the National Park Service. Conversely, if the body of water is deep enough in some places that sunlight cannot penetrate it, it's generally considered a lake.
When it comes to size, though, there are no exact guidelines. Ponds are generally smaller than lakes, but there's no universal standard. That means some things we call a pond might be considered a lake by some. And some lakes may be more pond-like to some people."
https://www.reconnectwithnature.org/news-events/the-buzz/whats-the-difference-lake-vs-pond/
A few years back, a woman drove her car into a small retaining pond off a highway and 2 of the kids in the car drowned. Everyone was amazed that a car could be completely submerged in such a small pond. Those suckers are deep!
https://www.twincities.com/2013/11/28/st-louis-park-drowning-accident-spurs-questions-about-retention-ponds/
But the sun shined on them while they drowned, so...
Actually there is a definition, from my old environmental engineering textbook: