I believe the term you are looking for is "Lactose Intolerant." This is when your body is unable to metabolize, or tolerate, a sugar found in milk and other dairy products called Lactose. A person with lactose intolerance (and who is therefore lactose intolerant) cannot digest the sugar, and so bacteria in the gut do, producing gas and making the person feel unwell.

The term is, as a matter of fact - lactose intolerant. BUT, if you were answering the question "What is Lack Toast and Tolerant?" then this would be the answer:

Let's break it up so that we can get to the bottom of this.

1. Lack Toast

You have a lack of toast.

You don't eat or have enough toast in your body.

Or maybe, you love toast and you don't have enough of it. "YOU HAVE A LACK OF TOAST!"

2. And Tolerant

And you're tolerant.

So, basically, you put up with it.

So, your answer would be: You don't have enough toast but you'll put up with it. (if possible!)