In a court of law, a dictionary can be a blunt weapon.

It provides meanings, to be sure, and context for arguments. But by its very nature, a dictionary rarely cuts to the heart of the matter.

This is particularly true when a case turns on the definition of a word, and the word itself is acquiring new meanings. At the recent meeting of the Dictionary Society of North America, in Vancouver, one of the speakers, Edward Finegan of the University of Southern California, told of his experience as an expert witness in a court case with such a word: gender.

What made gender a word of contention was its appearance as a category on a college application filled out by “a pre-operative transgendered student.” The birth certificate, issued when the student was too young to object, said the future applicant was male. But on the college application, the student’s choice was different. Under the category “Gender,” the student checked the box labeled “Female.”

The student was admitted, with a scholarship. But when the college found out that the student was biologically male, it dismissed the student on the grounds of fraud. Whereupon the student sued the college, saying that gender was a social or cultural matter, not biological, and that the choice was a matter of self-identity, not fraud.

Who was right? Well, what does gender mean nowadays? The expert looked to dictionaries to see if they could help, not only online Merriam-Webster and American Heritage, but also Urbandictionary.com, with its user-made definitions and user evaluations. Also considered were user responses to online Merriam-Webster questions, including “What made you want to look up gender?” Many respondents were students in social-science classes, Finegan said, who were not clear about the difference between gender and sex.

A dictionary, if it is to be of any use, has to reflect this ambiguity. Its definitions have to be broad enough to include the range of meanings a reader will encounter. So if you look up gender in Merriam-Webster’s Unabridged online, you will find two equally valid contemporary definitions: “sex” and “the behavioral, cultural, or psychological traits typically associated with one sex.” The college had interpreted gender by the first definition, the student by the second.

So who was right? The dictionaries, reflecting contemporary usage, refuse to decide. At best they confirm the range of possibilities. “In understanding and resolving such disputes,” Finegan said, “substantial value resides in consulting both established, reputable dictionaries and those that are crowdsourced.” And it does.

Which definition won in this case? We’ll never know — it was settled before trial, on motions for summary adjudication.