English is an interesting and international language. Non-native speakers probably never stop learning it.
I’ve stumbled upon a few odd words that describe an unnamed thing. Behold:
doohickey: a small object or gadget, esp. one whose name the speaker does not know or cannot recall: a garage filled with electronic parts and other valuable doohickeys.
whatchamacallit: used to refer to a person or thing whose name one cannot recall, does not know, or does not wish to specify: she wanted me to get the whatchamacallit from her bureau.
thingamajig: used to refer to or address a person or thing whose name one has forgotten, does not know, or does not wish to mention: one of those thingamajigs for keeping all the fireplace tools together.
Use these words sparingly. How do you like them?