1) an agreement that a person must keep to, especially one that has force in law; the document containing such an agreement (bond)

2) the action of sucking; the process of removing air etc to produce a vacuum and to force in liquid or dust; a similar process producing a vacuum that causes two surfaces to stick together (suction)

3) to push or put (something) suddenly and with force; the force in a jet engine that moves a plane; pressure by one part of a structure on another (thrust)