The term for a molecule that interacts with antibodies in immunology is called an antigen. Antigens are typically foreign substances, such as proteins on the surface of pathogens like bacteria and viruses, that trigger an immune response. When the immune system recognizes an antigen, it produces specific antibodies designed to bind to that antigen, aiding in its neutralization or destruction. The interaction between antigens and antibodies is fundamental to the body's defense mechanism, vaccination strategies, and the understanding of various diseases.