Thingamabobs are informal terms that describe objects whose names are either unknown or forgotten. The word "thingamabob" can be substituted by many other synonyms, some of which include "gadget," "doohickey," "widget," "dingus," "whatchamacallit," "gismo," "contraption," "apparatus," and "device." Each of these synonyms conveys the same meaning in that they refer to objects whose names elude the familiarity of the speaker or rememberer. Additionally, the use of these colloquial terms brings a sense of lightheartedness in communication and can be useful to avoid more technical/complex terms in friendly conversations.