Adhesion may refer to the joining of two different substances due to attractive forces that hold them. For instance, cohesion causes water to form drops and adhesion keeps the water drops on the surfaces of leaves and flowers in place.
Adhesion may also refer to the binding of a cell to another cell, such as a malarial protozoan cell (Plasmodium falciparum) binding to a liver cell via cell adhesion molecule called the circumsporozoite protein. This binding of the cells is referred to as cell adhesion.
Adhesion also refers to the fibrous bands that form between tissues and organs, often as a result of injury during surgery. An example is the interthalamic adhesion, which is a band connecting the two thalami of the brain.
Word origin: Latin adhaesiō, adhaesiōn-, from adhaesus, past participle of adhaerēre (to adhere)