What's the point in meaningless words?
1. Well, there are times when grammar dictates a word is required even though none is appropriate.
2. There are other times when we don't want to display our ignorance, so use a meaningless word that sounds impressive.
3. And still other times when we need to explain something but don't have the time or energy to trawl through a dictionary.
4. <your category here>

A recent example: I read an article describing a disease as 'idiopathic'. This comes under category 2 above, as it means, near enough, 'arising from some peculiar, unknown cause', but sounds informative.

Meaningless nouns (placeholders?) are especially useful under category 3: 'thingy', 'wotsit' or my personal favourite 'doobrie'.

So - do you know of any other meaningless words, that fall into any of the categories? Personal favourites as well as those used by others are valid, with bonus points for words that sound meaningful (category 2).

Fisk