A verbal agreement in law is almost always a spoken one.

https://thelawdictionary.org/article/the-law-of-verbal-agree...

That site can't even render HTML properly, and verbal means using words. That's the primary definition: https://www.dictionary.com/browse/verbal

Of course agreements are using words. How they express those words (orally or written) is the difference. Here's are better answers from actual lawyers: https://www.quora.com/What-is-the-difference-between-oral-an... and https://www.quora.com/Is-there-any-difference-between-an-ora...

> That site can't even render HTML properly, and verbal means using words. That's the primary definition: https://www.dictionary.com/browse/verbal

There exists separate legal dictionaries precisely because words take on new meanings in a legal context. Searching "verbal agreement" brings up numerous legal blogs and sites discussing what you are calling "oral agreements". They are likely interchangeable in a legal context.