Used as a verb, in a literal sense, "rebuilt" means to be built again after being destroyed or falling into disrepair. An example of this use is: "The church is being rebuilt after the earthquake."
Used as a verb, in a figurative sense, "rebuilt" means for something of a metaphoric nature to be built again after being destroyed or falling into disrepair. An example of this use is: "Her sense of confidence was rebuilt by the successful job interview."
Used as a noun, "rebuilt" refers to an instance in which something, especially related to a motor vehicle, that has been brought back into working order. An example of this use is: "The car's engine is not new; it is rebuilt."