The term 'tendency to stick together' is often referred to as 'COHESION' and is defined as the ability of a material or substance to remain intact when subjected to forces or stresses. COHESION is an important property of many materials, including liquids, solids, and gases. It is also an important factor in the formation of structures such as bridges, buildings, and other large structures. COHESION is also important in the formation of social groups, as it allows individuals to form strong bonds with one another.