Whatchamacallits are objects or things that we cannot recall the name or word for. Therefore, the antonyms for whatchamacallits may include specific terms or names that can describe the object or thing in question. A few examples of antonyms for whatchamacallits may be specific terms such as "laptop," "telephone," "television," "building," or "tree." These antonyms are used to replace the term whatchamacallits with a specific name or term, thereby identifying the object or thing in question. Other antonyms for whatchamacallits include "nothing," "void," "emptiness," "non-existent," and "unknown.", which convey the lack of knowledge or information about the object or thing.