Is the Dictionary Always Correct?

Earlier this month, our AIS teachers boldly declared that the dictionary is an extremely biased source that serves many stereotypes and acts of injustice against a variety of things. While some members in the class seemed stunned at this idea, I, for one, was not surprised at the notion. Every word in the dictionary has an origin of some sort, and this source has to have been heravily influenced by the time period surrounding it. Let's look at one example.
As we discussed connotations and denotations in American Studies this week, one of the terms that was brought up was the phrase "whitewashing". In the Merriam-Webster dictionary, it describes whitewashing first as to whiten with whitewash. Most interestingly enough, the second denotation of the phrase is to "deliberately attempt to conceal unpleasant facts about a person or organization". While the first use of the term has been dated back to the 16th century, the alternate usage of whitewash was first heard in the Era of Slavery in the United States. What significance does this have? During slavery, whites were considered superior to others, particularly blacks. So by whitewashing, the wealthy slaveowners would "cover up" the African-American's falts and truths in an attempt to rid them of their "unpleasant" background and assimilate them into American culture. This means the whites are trying to purify, to cleanse these slaves to become peaceful and graceful. I believe also that especially in the mission of the church, priests and missionaries wanted to remove all of the African-Americans' "sinful and dirty" culture and history and replace it with the holiness of white Christian beliefs, to "whitewash" over them. And since at the time, less than 1% of blacks were educated, the writers of the dictionary who coined the term were most certainly white. So this is one example of how the dictionary can be incorrect by using biases that the surrounding culture conveyed at the time.