a serving dish in the shape of a boat.
in the shape of, ie not actually the previous definition but referring to it in some way.
It is a serving dish, it refers in some way to a boat. It is not interchangeable with the first definition as anyone trying to use one for the other will quickly find.
Compare and contrast with
transitioned to being a woman.
Is/has become the previous definition. Was a man, is now a woman. Which if the previous definition is anything at all to do with sex, is not possible.
So your comparison fails.
What is the definition, or rather that common characteristics, of Woman which are found in all trans and cis women but no other females, and in trans women but not other males? And why are those characteristics more relevant than body sex when it comes to social and legal rights and protections against sexism?