The gender-neutral Mx. is used as a title for those who do not identify as being of a particular gender, or for people who simply don’t want to be identified by gender.
Titles are the short words that go in front of someone’s name. In English, the most common gender titles are”Mr.”, “Ms.”, “Mrs.”, and “Miss”. Now we also have “Mx.”.
The earliest example that we know of ‘Mx.’ is a 1977 article published in the United States, in an American magazine called Single Parent.
Emily Brewster, an associate editor at Merriam-Webster is added Mx. to the dictionary.
“Mx.” is pronounced as mix or mux.
It’s not clear whether or when Mx. will be fully adopted by English speakers.
Mx. was added to Merriam-Webster Unabridged in September 2017.