Mid-palate is a wine tasting term.
Two well-known tasting terms are the " attack ," the first impression you get when you put a wine in your mouth, and the "finish," the impression you get after swallowing the wine.
The mid-palate is between the attack and the finish and refers to the impression you get when you hold the wine in your mouth.
For example, if you taste a wine and feel its umami flavor when you hold it in your mouth, you would say that it has a "mid-palate umami flavor."