Synonyms For "Gismo" :
2 syllables:
doodad, gadget, gimmick, gizmo, gubbins, whatsis, widget
3 syllables:
appliance, contraption, contrivance, convenience, doohickey, doojigger, thingmabob, thingmajig, thingummy
4 syllables:
thingamabob, thingamajig, thingumabob, thingumajig