A more thorough explanation:

Definition: Horizontal nonprivity refers to the lack of privity between two parties when the plaintiff is not a buyer within the distributive chain, but one who consumes, uses, or is otherwise affected by the goods.

Example: A houseguest who becomes ill after eating meat that her host bought from the local deli is in horizontal nonprivity with the deli. This means that the houseguest cannot sue the deli for any damages caused by the meat because she did not buy it directly from the deli.

Explanation: The example illustrates horizontal nonprivity because the houseguest did not purchase the meat from the deli, but rather consumed it as a guest. Therefore, she is not in privity with the deli and cannot sue them for any damages caused by the meat.