Here's why it's confusing:
* Satchel: A small bag, often used for carrying books or other items.
* Mouth: The opening in the face through which an animal eats and breathes.
The combination of these two words doesn't make logical sense.
Perhaps you meant:
* Saddle mouth: A term describing a horse's mouth where the upper jaw is wider than the lower.
* Satchmo: A nickname for the famous jazz musician Louis Armstrong.
* A different word entirely: There's a chance you misheard or misspelled the word.
If you can provide more context or the source of the word, I might be able to help you understand its meaning.