Is there a difference between pretension and pretentiousness? Merriam-Webster gives the latter as one possible definition of the former.
Is one more recent than the other? Is there any reason to use one rather than the other when both seem appropriate?
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.
Ngrams for pretension vs. pretentiousness indicates pretension is and older word and is used more, and has been since before 1900. The shorter spelling may be one reason to use pretension where either word would work.
"Pretension" and "pretentiousness" are synonyms only when "pretension" is used in the sense of "5b. The unwarranted assumption of dignity, merit, etc.; the use of affectation to impress; pretentiousness, ostentation; an instance of this, " as in
1904 H. James Golden Bowl I. i. 24 He also took himself seriously—made a point of it; but it wasn't simply a question of fancy and pretension. (OED)
The Longman Dictionary of English Language and Culture (2005) adds that in this meaning the word "pretension" is formal and uncountable:
pretension: 2. [U] fml pretentiousness
In modern English, the word "pretension" is usually used in the sense of "5a. A claim or profession to be or have something, as a quality, skill, etc.". In this meaning, it is almost always plural - pretentions to something or to do(ing) something. Here, "pretension" and "pretentiousness" are not synonyms.
The authors of the MW Dictionary of Synonyms add that "pretension" is "rarely used as a concrete act, appearance, or statement" [emphasis mine - Alex B.].
Also compare the following examples:
She has a pretentious accent. => the pretentiousness of her accent [pretention is not possible here]
This song has such pretentious lyrics. => the pretentiousness of the song lyrics [?pretention is questionable here]
