/thing"euh meuh jig'/ , n. Informal.
a gadget or other thing for which the speaker does not know or has forgotten the name.
Also, thingumajig .
[ 1870-75; thingum or thingummy + JIG 1 , metrically patterned like GOBBLEDYGOOK, RIGAMAROLE; thingum perh. orig. from the gradational compound thingum-thangum (based on THING 1 ) with the same terminal syllable as in CRINKUM-CRANKUM, HARUM-SCARUM, trinkum-trankum, the ult. orig. of which is unclear ]