Technically your loins are your sides between your ribs and your hips, the same area of anatomy where a pork loin comes from. Your groin is where your thighs meet your hips. But both "loins" and "groin" are also used as a euphemism for genitals.
Unless you are talking about food, like loins or tender loins, or perhaps writing some sword and sandal fantasy about an Achilles like character, I wouldn't use 'loin' in this context.
"Loin" is a bit archaic, so I'd only use this if you're working with a historical setting or a fantasy setting based on historical settings.
IMO, loin is only for when you are going to eat it. Only exception being specific phrases such as "gird your loins".
That would make it simple, yeah.
Technically your loins are your sides between your ribs and your hips, the same area of anatomy where a pork loin comes from. Your groin is where your thighs meet your hips. But both "loins" and "groin" are also used as a euphemism for genitals.
Unless you are talking about food, like loins or tender loins, or perhaps writing some sword and sandal fantasy about an Achilles like character, I wouldn't use 'loin' in this context.
How I use it: loins = genitalia; groin = area around genitalia, but also including genitalia in some cases, mostly for men.
That's how I use it too, but it seems to be incorrect, which is why I googled it today.
Loin is like the area that shorts covers. Groin is the area a thong covers
Groin is what a loin does when he is angry. Just like in the Loin King.
Loin is the part of animal, including humans, between the Lowest rib and the hipbones.
I think a lot of romance novelists used loins as it sounds more polite than groin - which sounds more clinical.