thing·a·ma·jig also thing·um·a·jig 
(thĭngə-mə-jĭg′)
(thĭngə-mə-jĭg′)n.
Informal
Informal
Something whose name is unknown or forgotten.
[Alteration of obsolete thingum (from THING) + JIG1.]
- run short of
- run (something) up the flagpole
- run something up the flagpole
- runt
- run/take its course
- run through
- run-through
- runtiness
- run to earth
- run to earth/ground
- run to ground
- run to seed
- runty
- run up
- run-up
- runup
- run up the flagpole
- runway
- run with
- Runyon
- Runyonesque
- rupee
- Rupert
- Rupert Chawner
- Rupert River