A fine, very thin fabric, such as gauze. Tissue paper. A soft, absorbent piece of paper used as toilet paper, a handkerchief, or a towel. An interwoven or interrelated number of things; a web; a network: "The text is a tissue of mocking echoes\u201d ( Richard M. Kain). Biology An aggregation of morphologically similar cells and associated intercellular matter acting together to perform one or more specific functions in the body. There are four basic types of tissue: muscle, nerve, epidermal, and connective.