gizmo vs contraption

gizmo and contraption both are nouns.

Word	Noun	Adjective	Verb	Adverb
gizmo	Yes	No	No	No
contraption	Yes	No	No	No

As nouns, gizmo and contraption are synonyms defined as:

gizmo and contraption: a device or control that is very useful for a particular job

Other synonyms of gizmo include appliance, contrivance, convenience, gadget, gismo, widget.

gizmo (noun)	contraption (noun)
a device or control that is very useful for a particular job	a device or control that is very useful for a particular job
something unspecified whose name is either forgotten or not known