Learn English – When to use “nude” and when “naked”

They're pretty much synonyms, but I would argue that the longer word is actually more readily understood by the general populace (at least in America), despite what NGrams may tell you.

First of all, pretension is a more bookish term, so it would not surprisingly show up more in books. That does not mean it shows up more in speech or casual writing (especially online writing).

Second, pretentiousness is a noun made from the adjective pretentious, which virtually everyone knows and understands. You will hear the word used everywhere from literary soirees to shopping mall get-togethers to trailer-park barbecues.

Now, it is likely that most people would understand pretension if they stopped to think about it. They just wouldn't say it.

All right, having said that I am obliged to point out that pretension is much the better word to use with a complement. For example:

My wife can't stand her pretensions to culture.

You can't really say "pretentiousness to culture"; it just doesn't work.

And by the way, you won't hear the phrase "pretensions to culture" in a trailer park, unless said park caters to graduate students.

I think there's another difference: poultry is a subset of fowl. Either poultry or fowl can refer to domesticated or farmed animals. When referring to wild game, however, (e.g., pheasant, partridge, wild turkey), fowl is more applicable, whereas poultry is not.

Merriam-Webster's defines as follows:

poultry: domesticated birds kept for eggs or meat

fowl: (1) a bird of any kind (2) any of several domesticated or wild gallinaceous birds

Interestingly enough, my online dictionary says that gallinaceous includes "domestic poultry and game birds."