but we only have one word to name that object.
If "we" is referred to Italians, it is not exact, we also have two distinct words:
"cuscino" more general, may be referred to bed, sofa, etc. , or even technical application: "cuscino d'aria" as in an hovercraft, and so on.
"guanciale" is specifically a "cuscino" for the bed.
However in modern times "guanciale" sounds a little bit old-fashioned, and its use is declining in everyday use.
Yes Tim, this is a definitely a case of subtle differences between BE and AE...I followed the link to your "throw pillows" and they would definitely be referred to as "throw cushions" in England.
In BE a cushion is something you not only sit on and lie on...but also something you prop yourself up on (like a pillow!) when watching a movie on TV or reading a good book in bed. Then, when it's time to turn out the light, the "cushions" get thrown onto the floor (I'm a terrible housekeeper!) and one snuggles down into one's pillow(s) to actually go to sleep.