This connector is called a "barb" connector. This is an elementary as it gets.
The barb is made to connect a flexible hose to it. Any hose will do. A garden hose without a connector, flexible plastic hose of many types, semi-rigid plastic pipe, even pex if it is the correct size. Push an open ended hose onto it. Seal and secure the hose/pipe with a clamp or two. If it is a basic hose, then a basic clamp will do. Heat from a blow dryer can be used to temporarily soften the hose if the hose is a little to small to push onto the barb.
Ed Beal makes note that a hose that is to big or a clamp that is so tight that it dents the hose both decrease the life of the seal. Hoses come in many inside dimensions, and if you didnot get an exact match, then it is a good idea to lean toward a hose that is to small than toward a hose that is to big. Two clamps, if they can both fully fit into the barb is better than one over-tightened clamp.