The antonyms for the word "boards up" are "uncover," "unblock," "unseal," and "unveil." These terms convey the opposite meaning of closing off or covering a space or surface. For instance, when we say "unblock," it means to clear something that was obstructed or closed off. On the other hand, "uncover" means to remove a cover or lid from an object, revealing what's underneath. Similarly, "unseal" implies removing a seal or closure that was guarding something. Finally, "unveil" is used when removing a layer or cloth from something to expose its identity. These antonyms broaden the context of the original word, providing a plethora of creative possibilities for use.