Bound together is a phrase that describes the act of connecting two or more things in a secure manner. TIED, JOINED, and CEMENTED are all words that can be used to describe this process. TIED implies the use of a rope or string to bind two objects together. JOINED suggests a more permanent connection, such as welding two pieces of metal together. CEMENTED implies a strong bond created by using a type of adhesive. All three words can be used to describe the concept of being bound together.