voider

The word "voider" usually refers to a person, thing, or clause that makes something void, meaning no longer valid or legally effective. It does not mean someone who merely avoids a duty; instead, it points to something that removes force, standing, or effect from an agreement, claim, or document. In that sense, the word fits best in formal, legal, or technical contexts. For example, a clause in a contract or will could act as a voider if it causes the whole document, or part of it, to lose its effect when certain conditions are not met.

Outside that main meaning, "voider" also appears in older historical writing with two well-known senses. In household use, it could mean a tray or basket used to remove scraps and dishes from the table, literally clearing the table away. In armor, it could mean a piece of mail worn to protect the uncovered gaps between plates, such as under the arms or at the joints.

The word can be stretched in a metaphorical way for someone who regularly cancels or wipes out plans, but that is not its usual use. Overall, it remains a formal and somewhat historical term. It is most helpful when you want a noun for something that cancels validity, while also carrying a couple of older meanings that may appear in literature or historical texts.