"Thingumajigger" is an informal and colloquial term used to describe an object whose name is not immediately known. There are several synonyms for this word, including "doohickey," "whatchamacallit," "thingamabob," and "doodad." All of these words are used to describe objects whose names are not known, such as parts of machinery or tools. These words have been used for many years and have become a part of everyday language. They are useful when trying to describe something without knowing its official name, but are often used in a playful or lighthearted way. Whether you call it a thingumajigger or a doohickey, the important thing is that the object is identified and understood.