Milkshake duck is the Committee's Choice for the 2017 Word of the Year at Macquarie Dictionary (but not necessarily the public's choice -- the public are being asked to vote on their Word of the Year at the Dictionary's website). A milkshake duck is "a person who is initially viewed positively by the media but is then discovered to have something questionable about them, which causes a sharp decline in their popularity". As Macquarie Dictionary says, the word may not be familiar to everyone, but we are all aware of the phenomenon. The word comes from "an internet meme started in 2016 by an Australian cartoonist who posted a tweet about a duck supposedly made famous for its adorable nature and habit of drinking milkshakes, but which is (sic) almost immediately discovered to be racist".
Macquarie Dictionary has anticipated that some people are going to ask how the Word of the Year can be milkshake duck, which is two words. It explains that when it uses the word 'word' it actually means 'lexical item' or 'lexical unit' (see here).
The Committee gave honourable mentions to the words endling and framily. An endling is "an individual that is the last of its species, its death resulting in the extinction of the species, as the last known thylacine, which was kept in Hobart Zoo until its death in 1936", and a framily is "a group of people who are not related by blood, but who constitute an intimate network".
The other words that made up the short list were big sugar, bike sharing, daigou, dark state, dopamine dressing, makerspace, plandid, poke, subtweet, technology doping, text neck and transhumanism. If you like one of these words, or, indeed, if you prefer milkshake duck, then you can vote for your choice for Word of the Year until 22 January here.