A term of art used in patent claim language, which means that to infringe, the accused product or process must include at least those elements recited following the “comprising” or their equivalents, but may include additional elements, e.g., if the claim says comprising a+b+c, something containing a+b+c+d could likely infringe, but a product with a+b+d would usually not (unless d was the equivalent of c). Such a claim is also usually described as an Open Claim. See Claims, Closed Claim, Consisting of.