A tenocyte is a cell in a tendon. It can also be referred to as a fibrocyte, although not all fibrocytes are also tenocytes.
Tendons are mostly extracellular matrix (ECM) - in other words, non-cellular biomass, the space in between cells. The ECM is mainly composed of collagen fibers that are secreted by the tenocytes and organized into bundles. There are also proteogylcans, proteins attached to long carbohydrate chains.