Is a guard in a prison and probably not interpretable in any other way. The "usually a man" is either sexist bias or purely encyclopaedic information. Compare jail guard, jail inmate (both well attested on Google Books). Equinox◑ 01:19, 18 February 2012 (UTC)
Keep per Wiktionary:COALMINE this is clearly the most common word for this occupation and is useful for translations, this is shown by the massive availibility on google books for prisonguardsee here.#* 2005, Ernie López, Rafael Pérez-Torres, To Alcatraz, death row, and back: memories of an East LA outlaw, page 81
As we disembarked, I saw a prisonguard wrap the anchor rope around a post and then place a chain around the looped rope and secure it with a padlock.
2006, Stephanie Hepburn, Rita James Simon, Women's roles and statuses the world over, link
Men are required to serve either in the police force, the prisonguard service, or in one of the military economic service units.
2007, Robert Baer, Blow the House Down: A Novel, page 148
Instead, a striking, petite woman in a sky-blue prisonguard uniform met me on the other side.
And your other quotations all use hyphenated prison-guard as an adjective, except the last hyphenated Marilyn-the-prison-guard. When hyphenated words wrap at the end of the line, Google Books interprets them as unhyphenated. ~ Robin 06:25, 19 February 2012 (UTC)
Keep. To me this feels very much a set term. It is more than 10 times commoner than ‘jail guard’ (180,000 v. 14,000 on b.google); and it's also in the OED (in the ‘compounds’ section of prison). Ƿidsiþ 07:45, 19 February 2012 (UTC)
Fine, well here are three that are indisputably oneword not one-word/one- word/one word situationals.one, two, three.Lucifer 09:30, 19 February 2012 (UTC)
Number three seems to be a misspelling of Telfair (State) Prisonguard tower; it is capitalised and makes more sense in the context. It probably can be verified with usenet quotations though, so for the sake of fairness I'm changing my vote to abstain. Ungoliant MMDCCLXIV 15:51, 19 February 2012 (UTC)
This bloody COALMINE is more trouble than it's worth. Hint: if you can dig up three probable scannos for something like happyperson, which represent practically none of the actual usage, then you are probably abusing it. Equinox◑ 22:40, 19 February 2012 (UTC)
I found three obvious non scannons, they are literal scans of the original work that can be seen as clearly one word. This clearly shows that this term is widely used as a set term. Also even coal mine is just a mine dedicated to coal. But so what? Someone that doesn't know that would not know how to break apart the terms. Also prison guard/prisonguard isn't just guarding a prison, its more of a job of guarding the prisoners and preventing their escape and disciplining them. Prison guards are present even when jails are not, such as chain gangs, and for transport. That is a richer meaning than the sum of parts. I call bs. Happyperson is just an adjective+noun, prisonguard is a set term and a common occupation.Lucifer 00:49, 20 February 2012 (UTC)
Keep per Lucifer; a prison guard is still a prison guard even if they never set foot in a prison, or never guard a prisoner. As for WT:COALMINE, it requires that the term be "significantly more common than a single word spelling that already meets CFI". Correct me if I'm wrong, but scannos do not count towards meeting the CFI, do they? Otherwise, we should amend the CFI to be clear that a scanning error by itself is not a countable use of a word. bd2412T 16:54, 20 February 2012 (UTC)
Scannos certainly don't count. The citations that aren't scannos seem more plausibly interpreted as typos or typesetting errors than a alternative forms. "Prisonguard" is very rare compared to "prison guard", which suggests error.
As for Luciferwildcat's argument, a rental truck maintains its identity even when it is not under rental or even available for rental and an ice cube tray maintains its identity even when empty or when it only has water or wax or orange juice in it. It is hardly unusual that an NP is SoP under these circumstances. DCDuringTALK 17:51, 20 February 2012 (UTC)
First, rental is an adjective indicating availability for rent. Although abbreviation has led to noun usage ("it's a rental"), a truck is not a rental truck unless it is or has been available for rent. On the other hand, we absolutely should have an entry for ice cube tray. If I get a cafeteria tray and pile ice on it, does that make it an ice tray? If I take a tea tray, fill it with water, and put it in the freezer, is that an ice tray? bd2412T 17:59, 20 February 2012 (UTC)
I do not agree that "rental" is an adjective. It does not meet the usual criteria: is not comparable etc. Equinox◑ 20:49, 2 April 2012 (UTC)
When I came up with WT:COALMINE, the idea is to avoid the situation where the commonest form doesn't mean CFI but a much less common form does. Mglovesfun (talk) 18:33, 20 February 2012 (UTC)
Every example cannot be scanno or error simply because you wish them to be.Lucifer 19:58, 20 February 2012 (UTC)