It is the principal ingredient for the Aveeno line of products.
The two principal ingredients do not do much for each other.
It simply names the two or three principal ingredients in each dish and then shuts up.
In extreme cases, the menu might simply name the principal ingredient and the cooking method.
Thymus was the principal ingredient, and he approved of its use on his person.
"The principal ingredient of our family meals was love and security," she writes.
I mean the way that they obtained one of the principal ingredients was hellish.
One of the principal ingredients necessary for success is simple hard work.
But the list of ingredients names vegetable oil as the principal ingredient.