The Cambridge Dictionary has updated its definition of "woman" to include anyone who "identifies as female", regardless of their sex at birth.
Why?: The definition of "woman" has been expanded to include transgender women.
What's the change?: The Cambridge Dictionary now states that in addition to being defined as an "adult female human being," a woman can also be “an adult who lives and identifies as female though they may have been said to have a different sex at birth."
"Mary is a woman who was assigned male at birth," the dictionary states as an example.
What else you must know: A similar change has been made to the definition of "man." The word may now be used to define "an adult who lives and identifies as male though they may have been said to have a different sex at birth."