When we cannot recall or do not know the name of a person or thing in English, we tend to substitute the name with funny-sounding words such as thingy, thingumabob, thingamajig, or whatchamacallit.
In Italian, the corresponding term is coso (masculine, plural: cosi), a derivative of the word cosa (thing / object / matter). It is often, though not always, used in a pejorative sense.
Dammi quel coso lì sul tavolo!
Give me that thingy over there on the table!
You can call someone coso when you don’t know his name (or cosa if it’s a woman), but be aware that it sounds diminutive and lacks respect, as if the person speaking doesn’t want to make the effort to ask for the other person’s name.
Whereas coso can substitute pretty much any noun, the verb cosare may take the place of any verb that you don’t know, cannot remember or should not say including fare (to do), essere (to be) and avere (to have).
Che stai cosando?
What are you doing?
(lit: What are you thingamabobing?)
Some possible synonyms for coso include:
- cosa = thing / object (the word from which coso derives)
- come-si-chiama = what’s-it-called
- aggeggio = gadget, contraption, thingy
- arnese = device, contraption, gizmo
- roba = stuff, things