I did a dumb thing a few years ago, soon after I got my green card. I had a "date" with a woman who charged me money. I got caught by the police, and now "soliciting a prostitute" is on my criminal record.
I would like to apply for U.S. citizenship as soon as I am able, and I haven't had any other arrests, but I see that one of the questions asks whether I have "procured anyone for prostitution." What exactly does that mean? And if I check yes to that, will I automatically be denied U.S. citizenship?
The word "procure" in this context means to act as a procurer or pimp, who induces others to engage the services of a prostitute. (This definition was discussed by the Board of Immigration Appeals (B.I.A.) in a case called Matter of Oscar GONZALEZ-ZOQUIAPAN, 24 I&N Dec. 549 (B.I.A. 2008). The B.I.A. said that although, "The dictionary meaning of the word "procure" is generally to obtain or acquire," . . . "as applied to prostitution, it has a specific meaning, i.e., ‘[t]o obtain [a prostitute] for another.' Webster's II New College Dictionary 882 (2001).")
Therefore, what you did does not fit the description on the question in Form N-400. You should be able to truthfully answer "No" to this question. That at least avoids being faced with an automatic, statutory bar to naturalization based on lack of good moral character.
But that's not the end of the analysis. You will not be able to hide this arrest, and will need to answer "Yes" to the various questions about whether you have been arrested or charged or convicted of a crime. Because of this, you will need to give U.S. Citizenship and Immigration Services (USCIS) details about the arrest and conviction (such as the place and date) and documentation showing the outcome.
USCIS can take a conviction for soliciting a prostitute into account in determining whether you have good moral character. In the worst-case scenario USCIS could accuse of having committed a crime involving moral turpitude (CIMT), which can in some circumstances, depending on the timing and length of sentence, lead to deportation. (See I.N.A. § 237(a)(2)(A)(i).)
Even if USCIS doesn't accuse you of a crime of moral turpitude, you will likely need to work extra hard to prove your good moral character, such as by obtaining a letter of support from your religious leader and demonstrating that you live a responsible life, work hard, do volunteer work, and so forth.
Also a possible strategy is to wait a full five years from your conviction before applying for citizenship. (That five years represents the number of years that most people must remain in the U.S. as permanent residents before applying for citizenship, though it's less time in a few cases, as described in When Can I Apply for U.S. Citizenship?.) The idea here is that you can more easily show good moral character for the entire period that USCIS looks most closely at when assessing whether you have good moral character.
USCIS can look further back in time than those five years, and will definitely consider your arrest no matter how far back in time it occurred. Nevertheless, if your record looks clear for the whole required five years of permanent residence, USCIS will give much less weight to what happened before that.
With this complicating factor in your case, and the need for added documentation, you would definitely be best advised to hire an experienced immigration attorney for help. Also speak to an attorney before traveling outside the U.S., as your conviction could block you from reentering on grounds that you're inadmissible.