I happen to like superannuated, not when it refers to me but if used for words or ideas that are obsolete, out of date, too old to be useful. But it's not a word I recommend for everyday use: some words should be saved for special occasions.
I thought about the currency of language this week while watching a Sherlock Holmes story in which a character called himself a "valetudinarian," and I thought, first, does it mean what I think (invalid or hypochondriac)? Yes, it does and it fits in a Victorian bit of dialogue. Would we use it today? Probably not, unless we are trying to impress people with our love of obscure, Latinate words.
A friend of mine tends to think, along with the late Wm. F. Buckley, Jr., that every word in English has some place in the language and should be used. I tell him this is nonsense since some of the words marked in the dictionary as "Obsolete" or archaic have fallen out of use; others are simply too technical for ordinary use in standard edited English for the general reader.
Take interstices, for example: I remember it from Dr. Johnson's 1750 Dictionary. It is still used in science to mean tiny openings or crevices; general use of this word seems pretentious and confusing. If the reader is puzzled by such an odd word, it seems to me I as the writer have failed to be clear and idiomatic. To take a word, useful in technical writing, and move it into general circulation is what we call jargon. Usage is all about the context of the words we use.
Here are some other words that are, or should be, obsolete: peradventure, obloquy, hussy, gustation. Pusilanimous would not be missed since we have the words cowardly, timid, even dastardly, if we want a bit of old-fashioned color. Procumbent surely would not be missed (just say prone, prostrate). The short, Anglo-Saxon word is often better than the Latin-originated word like impecunious, an unnecessary word in a language that has penniless, indigent, even the more general poor.
The following words are officially obsolete, according to an online dictionary: caddish, coiner (for counterfeiter), costermonger, kine (cattle), nought, and withal (mentioned above).
In reading a New York Times review of the 1955 film noir classic Night of the Hunter this week, I found the word "withal" to mean "nonetheless." A clear sign that the review was written in 1955 by a highly literate writer of that era who would probably say "postman" and have no trouble with "valises" instead of "suitcases." Some words, like these last two, drop out of ordinary discourse. Language is a constantly changing thing, though we who are writers and editors approach such changes with caution and care.
When I hear the word "pocketbook," I often think that this word should have given way to purse, wallet, billfold, but somehow it is still used. It reminds me of my otherwise cool, hip students who insist on using amongst (for among)
and unbeknownst, which sounds truly antique and superannuated to my ears.
Logic and reason have as little to do with usage, it seems, as they do with love.