contraption
n.n. a complicated machine or device that looks strange or is difficult to use. You use this word when something feels more like a piece of junk than a useful tool.
n. a complex, often awkwardly constructed machine or device. Frequently carries a negative connotation of being overly complicated or aesthetically unpleasing.
The old man tried to fix the broken contraption.
The inventor spent months building a strange contraption that could supposedly clean the entire house in one hour.
While the device was technically a marvel of engineering, its unwieldy design made it more of a contraption than a practical tool for everyday use.
Possibly a Western US English dialectal word of unknown origin. Perhaps from contrive + trap + -tion, while also possibly approximating construction. Chambers suggests contrivance + adaption. Neither Chambers nor Concise Oxford suggests a US origin. Compare cantrip, cantrap (Scots dialect), a wilful piece of trickery.