Every Word In Context

Every word in a document, record, or newspaper account needs to be kept in context. The precise meaning of a word may have been different in 1800 than it is today. A word being used in a legal document may have a meaning that is more specific than when used by a layman and may have a slightly different meaning than in common conversation.

Is there a word or phrase that you could be interpreting in a 21st century way--and not the way it was meant when it was used in the document?