thing ‧ a ‧ ma ‧ jig /ˈθɪŋəmədʒɪɡ, ˈθɪŋəmɪdʒɪɡ/ BrE AmE ( also thing‧a‧ma-bob /ˈθɪŋəməbɒb, ˈθɪŋəmɪbɒb $ -bɑːb/ thing‧y /ˈθɪŋi/) noun [countable] spoken
[ Date: 1800-1900 ; Origin: thingum 'thingamajig' (17-19 centuries) , from thing ]
1 . used when you cannot remember or do not know the name of the thing you want to mention:
What do you call that thingamajig? You know – the circle with the line through it.
2 . British English used when you cannot remember or do not know the name of the person you want to mention:
Is thingy going?