It's natural, when you see Wikipedia for the first time, to mistake it for a dictionary. Many of the entries, at present, are brief. So some people start an article, listing several senses of a term, and then stopping working on that article, as though they were interested only in giving the meanings of various terms.
This is not a habit to be encouraged.
Nearly everyone here agrees that brief, "stub" articles are to be encouraged. There are some differences of opinion as to whether just definitions are acceptable. If you want to make everybody happy, add a little encyclopedic information of some sort. Don't just give the meanings of the word. If you do just give the meaning of the word, nobody is going to be mad at you (except maybe Larry Sanger, but then, he gets mad at everybody :-) since he cares about Wikipedia so much). They'll simply take the entry to be a "stub" article, which will be expanded later. That's probably OK, in most cases.
Moreover, there are plenty of senses of terms that aren't of interest in an encyclopedia. They would be, in a dictionary, but Wikipedia isn't a dictionary. So it makes no sense to describe those other, mere dictionary senses of terms in Wikipedia articles (unless, somehow it is important to describe those senses in order to clarify the main topic of the article).
While on the one hand we are all certainly delighted that Wikipedia is growing in breadth, some (but not all) of us view breadth at the expense of the very notion of what we are working on--an encyclopedia--as a bad idea.
See also what Wikipedia is not.