Wikipedia:You are probably not a lexicologist or a lexicographer

When edit wars occur over the lead paragraph of a controversial topic, people may turn to more NPOV sources, like the dictionary. The dictionary is one source among many that is generally considered more authoritative than personal opinion.

Sometimes, for complex topics like homophobia, marriage, or truth, the dictionary seems inadequate. Wikipedians can and do argue over whether the definition is accurate, or which sense of a word is prevalent in mainstream usage. You may not like the dictionary definition, but if it is a reputable dictionary, it generally carries more weight on Wikipedia than your personal opinion. On average, you can't make it disappear from the article simply by claiming that "it is a bad definition" based on your (explicitly or implicitly asserted) status as an expert on the writing of dictionaries. This is because you are probably not a lexicologist or a lexicographer.

Let’s face it, you are probably not trained in lexicology or lexicography. You may have opinions about semantics (how words are defined or used within a lexicon), or how you would have written the dictionary, but your opinion does not countervail the efforts of trained lexicographers.

What to do
When faced with a dictionary definition that you disagree with, your alternatives are limited; you can either find a better dictionary with a better definition, or you can cite reputable sources that discuss the changing meaning of a given word. What you cannot do is discount the definition by claiming to know a lot about words and dictionary writing. You are probably not a lexicologist or a lexicographer. Even if you are, you still need to cite sources.

Arguments against using the dictionary definition in the lead paragraph
Not all Wikipedians agree with these sentiments. Several arguments are as follows:


 * Modern dictionaries are likely to be in copyright, and a definition may or may not be acceptable fair use (Wikipedia's guideline on non-free content states that "brief quotations of copyrighted text may be used to illustrate a point, establish context, or attribute a point of view or idea"). Older, public-domain dictionaries may have anachronisms or outdated definitions.
 * Since Wikipedia is not a dictionary (see WP:NOT), some editors think that using dictionary definitions to start an article makes it sound more like a high school essay than a reputable encyclopedia. Stylistic opinions count in Wikipedia, so this is a legitimate point that should not be dismissed lightly.
 * Dictionary definitions, though accurate, often do not convey the full connotations and context of the use of a word. The large space we dedicate to each article allows us to explore these details. While a dictionary definition may be an appropriate component of a lead paragraph, it is rarely a sufficient exposition of the subject.
 * Dictionaries are extremely conservative in what they recognize, and are descriptive of an existing definition, not creators of it. More immediate sources, like books, academic writings, or others are often more direct and accurate, especially when they are responsible for the definition in the first place. Stephen Colbert is a much better source for a definition of truthiness than Webster's.
 * Original sources may have a more nuanced and in-depth treatment of definitions; for example, Plato's Republic and other philosophic inquiries into the meaning of justice may occasionally outweigh dictionary citations. Then again, Plato is a published source, and you are probably not Plato.