There are a lot of names that aren't really used anymore; names that were quite common or at least fairly well-known in the past. While there may still be a few people with these fine monikers, at present they are a rarity. Of course, there's no telling what the future holds, and names have an interesting way of coming and going with the passage of time. There may be a resurgence in popularity for one or more of these, but at present they're virtually extinct.
Ebenezer: Here's a name that was all the rage in the 17th & 18th Centuries, and I have more than one ancestor named Ebenezer. There is a whole string of Ebenezer Inghams starting with Uncle Ebenezer born circa 1661, going 5 generations until the tradition was finally ended. We're all very familiar with this name thanks to Charles Dickens, but that may also be its downfall. After the popularity of "A Christmas Carol," nobody wanted to name their kid after Ebenezer Scrooge, though it's really a shame. The whole point of the story was about Ebenezer becoming a good man in the end, so maybe people missed the point? Well, whatever the cause, Ebenezer is a name that has been put into retirement, and might never be used again.
Effie: During the latter half of the 19th Century and into the early part of the 20th, this was a fairly common lady's name. One of my father's grandmothers was Effie, and my mother's grandmother had an Aunt Effie. It has since passed into obscurity, and it is doubtful it will return. One reason that may keep it from becoming popular again is its similarity to the term Effing that people tend to use when they don't want to come out and say the F-word. "It's an Effin' shame that Effie is no longer a common name."
Elsie: You still see this one on rare occasion, mostly among those over 50, but it seems this name is on its way to the museum. My wife's middle name is Elsie, because her grandmother was Elsie Merle Henry, though I don't know of anyone else with this as a first or middle name. A lot of people seem to call their cows Elsie, too, so that might be another deterrent to giving it to a child.
Erastus: At the time of the Revolution, this wasn't such an uncommon name. There were several Inghams named Erastus, but time has pretty much wiped the name out. You don't see it used much after 1800, and I don't know if there's a man alive today with this name.
Gaylord: While never a very common name, it was widely used even into the 20th Century, but thanks to modern slang I fear this name is on the way out. Since "Gay" now means homosexual, it is doubtful that many people are eager to make their children the target of ridicule or controversy with this old stalwart. Gaylord is another sad victim in the culture war.
Grover: Not since President Grover Cleveland has this name been really popular, and these days it seems the only creature to carry the name is that blue Sesame Street Muppet. Grover isn't really a bad name, it just sounds a little old-fashioned. Maybe it'll come back someday.
Jemima: For most Americans, the first thing that pops into their mind is the lady on the pancake syrup bottle, but throughout the 17th and 18th Centuries it was a pretty standard name for a lady, black and white alike. Now, it's pretty much a joke thanks to commercialism and stereotypes. I don't see a resurgence of Jemimas on the horizon.
Mehitable: Sometimes spelled Mehitabel, this is another classic from the 18th Century which has faded into disuse. You don't see it much after the early part of the 19th Century, though I have used it for a character in West of the Warlock.
These are just a handful of names that I've noticed, and that's not to mention the many rare or obscure names that I've discovered in my genealogical research, like Alzina or Marsilva. Of course, I have nothing but respect for these names I've mentioned, and do not suggest that there is anything wrong with them, only that they are currently out of vogue with the mainstream of society. If you happen to be named Grover Erastus Gaylord, the fourth, please take no offense from my words.