The term "un-hook" refers to the act of separating or disconnecting objects that are hooked or connected together. The antonyms or opposites of "un-hook" are connect, join, couple, attach, and fasten. When we talk about connecting objects, we mean bringing two or more things together, forming an attachment that keeps them united as one. Joining, on the other hand, means attaching something to something else of the same kind to create a larger object. Coupling refers to combining two things so that they work together as one unit. Attaching is the physical act of connecting two things together through a fastening mechanism. Finally, fastening involves joining or attaching things firmly such that they cannot be easily separated.