{This question came to mind because of the recent question .. What do you call the interconnecting bits of a puzzle piece in English? }
In my opinion, in English, it's reasonably common that—strangely enough—there is no word for a certain reasonably common thing. And indeed, speakers prefer to use an ad-hoc description for the thing in question on an ongoing basis, rather than, as you'd probably expect, a specific or technical word falling into general use and coming to be "the word" for the thing. {Contrast milieu such as say Germany or Japan, where the culture, within 12 seconds, codifies exact, specific, universally-accepted terms for anything that comes along, whether a cultural phenomenon, technical object, or the like.}
I think of this as "the Thingy substitution", or the things in question as 'thingy things' because, well, they are usually referred to as
the thingy that...
The perfect example is
the thingies on jigsaw puzzle pieces.
(Note that, 100% of English-native speakers will understand exactly what I am referring to.)
To repeat, native English speakers—in my opinion—prefer to stick (even over decades) with ad-hoc thingy-esque multi-word descriptions rather than adopting a new word generally accepted.
{On the other hand, of course, the etats-unis in particular is notorious for generating zillions of acronyms and other coinages—however, I don't think the two concepts are at odds, both are true.}
Now there's possibly a term for this phenomenon among linguists e.g., "grasp words", "thingy words" or "ad-hoc non-naming conventions" etc.
(a) Does anyone know such a term?
(b) Indeed, does anyone agree that this is a phenomenon amongst particularly English speakers?
(c) Indeed, is this all well-known and explored by academic linguists/etc and I'm just behind the times?