From The Oxford Guide to Practical Lexicography, by Sue Atkins and Michael Rundell:
Most people would agree that words have meanings, sometimes multiple meanings. But meanings and dictionary senses aren’t the same thing at all. Meanings exist in infinite numbers of discrete communicative events, while the senses in a dictionary represent lexicographers’ attempts to impose some order on this babel. We do this by making generalizations (or abstractions) from the mass of available language data. These generalizations aim to make explicit the meaning distinctions which—in normal communication—humans deal with unconsciously and effortlessly. As such, the “senses” we describe do not have (and do not claim) any special status as “authoritative” statements about language.