High Quality Content by WIKIPEDIA articles! An adhesive, also known as glue, is a material, typically liquid or semi-liquid, that adheres or bonds items together. Adhesives come from either natural or synthetic sources. The types of materials that can be bonded are vast but adhesives are especially useful for bonding thin materials. Adhesives cure (harden) by either evaporating a solvent or by chemical reactions that occur between two or more constituents.