Social discussion surrounding gender identity has heightened over the last few days since popular singer Sam Smith came out as non-binary and announced that they would exclusively be using they/them/theirs pronouns.
Although the singular 'they' has been grammatically correct since the creation of the English language (just an FYI), in the midst of a lot of confusion regarding its use, the Merriam-Webster Dictionary has officially included a definition of "they" as a non-binary pronoun.