a device or control that is very useful for a particular job
"The new app is an essential gadget for managing my daily schedule efficiently."
A thing whose name cannot be remembered; thingamajig, doohickey.
"He fumbled in his pocket trying to remember the name of that strange gadget holding up his shirt collar."
In plain English: A gadget is any small, clever tool designed to make your life easier by doing something specific automatically.
"He used his new camera gadget to take pictures at the concert."
Usage: Use "gadget" to refer specifically to a small mechanical or electronic device with a useful function, rather than the vague placeholder terms like "thingamajig." It implies that the object is recognizable as technology even if you cannot recall its specific name.
The origin of "gadget" is unknown, though it likely derives from either a French word for a trigger or the surname of a French industrialist named Gaget. The term first appeared in English print in 1886 when Robert Brown used it to describe small mechanical devices.