In the case of a thing
Anything which is unnecessarily added onto something; used especially when such addition impedes
the full functionality
or greatly increases the expense
it. The object itself may be frivilous if it is unnecessary in it's setting. See SUV
In the case of an action:
To deliberately go through a large amount of time and effort to achive significantly less result than what was justified for the effort. See Rube Goldberg.