What Does It Mean to Discriminate Because of ‘Sex’? How the Legal Meaning of That Word Has Evolved

Words that seem short and simple often conceal the greatest complexity in meaning. The longest entries in the Oxford English Dictionary are not for long words but the multifarious run and set.

The same is true for the word sex, three little letters that remain utterly contentious half a century after they wound their way into the United States' most historic civil-rights legislation.