Meeting room or meetings room [duplicate]

Solution 1:

As a rule, the singular form is used for the first part of a compound noun. So, when in doubt, use the singular. There are three kinds of exceptions:

1. If the singular would be ambiguous, as in "a singles bar": a single bar means just one bar.
2. If the plural used to be a singular possessive, which sounds the same: I think "ladies man" (a man who likes flirting with women etc.) comes from the possessive "lady's man", which is also used. It might also be partly due to category 1, since a "lady man" is now generally an effeminate man.
3. Okay I lied. This is not really a category. There just are exceptions. Often (but not always) the plural is used because a certain word is usually heard in plural in a certain sense, such as "trades union" and "weapons development". I also believe "clothes rack" is fairly acceptable nowadays. It seems the trend is towards using the plural more than in the past, which some traditionalists abhor.