The first two rounds of the 2022 Australian Open are done and dusted and the Melbourne Slam is gearing up for its fifth day of action on Friday. Novak Djokovic's visa saga has been eclipsed by some truly wonderful tennis as the focus has shifted to the action on the court.But over the last couple of days, there have been several incidents that have left players quite baffled. Viewers watching the tournament on television may have heard a chorus of what appeared to be boos directed at players in between points, creating a rather unique and hostile atmosphere in the stadium.However, those are not boos, but rather cries of "siuuuu" made popular by Manchester United forward Cristiano Ronaldo and his legion of followers.What does "siuuu" mean?The Siuuu celebration was first "invented" by footballing superstar Cristiano RonaldoSiuuu, on its own, does not really mean anything. However, from a sporting standpoint, its origin can be traced all the way back to a preseason friendly between Real Madrid and Chelsea at the International Champions Cup.Cristiano Ronaldo celebrated his first goal with a leap into the air while shouting the word "Si". The exultation - translated into English as "yes" - was meant to denote his joy at scoring a goal.Ronaldo has since modified the move, and "siuuu" is synonymous with his success. After winning the 2014 Ballon d'Or the Portuguese acknowledged his fans with the same scream of delight.Ronaldo himself confirmed as much during an interview in 2019. The midfielder disclosed that he has stuck with the celebration because of its association with success in the minds of his fans."When we would win [in Spain], everyone would say 'siiiii' and so I started to say it. I was in the USA and we played against Chelsea [in 2013]. I just scored the goal and it just came out. It was just natural," Ronaldo said. "Since then, I started to do it more often and the fans see it and they're like 'Cristiano, Siiiiuu'. People are reminded of me because of it, so it's good. I'll continue doing it like that."Since then, Manchester United's Jesse Lingard, Indian cricketer Mohammed Siraj, French footballing prodigy Kylian Mbappe and many other athletes have imitated the celebration.ESPN UK@ESPNUKCambridge celebrated knocking Newcastle out of the FA Cup by hitting the SIUUU.Cristiano Ronaldo's impact on football is ridiculous 9:00 PM · Jan 9, 2022178332947Cambridge celebrated knocking Newcastle out of the FA Cup by hitting the SIUUU.Cristiano Ronaldo's impact on football is ridiculous 😅 https://t.co/pZ9RmaPJ4xWhy are fans at the Australian Open chanting "siuuu"?Honestly, nobody knows why fans at the Australian Open are chanting it. It seems to have become a trend amongst youngsters, with the "siuuu" celebration taking social media by storm, just like the "dab" a couple of years back.CristianoXtra@CristianoXtra_Fenerbahçe voleybol team doing Cristiano Ronaldo's iconic SIUUU Celebration.Most iconic celebration in the history of sports. 10:41 PM · Jan 16, 20228716Fenerbahçe voleybol team doing Cristiano Ronaldo's iconic SIUUU Celebration.Most iconic celebration in the history of sports. 🐐https://t.co/Gfja8dL8DuHow do players feel about the chant at the Australian Open?Like most players, Daniil Medvedev was not a fan of the chant at the Australian OpenUnsurprisingly, most players have expressed their displeasure at the chant. Nick Kyrgios compared fans performing the chant at his first-round match against Liam Broady to animals in the zoo."It's just stupid. I can't believe they did it so much. I thought they were going to do it for like 10 minutes. They did it for two-and-a-half hours, like every point," Kyrgios said. "I don't know why. It was a zoo out there."ESPN UK@ESPNUKAndy Murray on the fans shouting SIUUU after his Australian Open win 4:00 PM · Jan 18, 2022396393116Andy Murray on the fans shouting SIUUU after his Australian Open win 😅 https://t.co/VQ5Kdi1aufFormer World No. 1 Andy Murray said he found it "incredibly irritating," but was a little relieved that he was not being booed like he originally thought."Initially, I thought it was booing because there were some people booing during my practice yesterday. And it was incredibly irritating."The Tennis Podcast@TennisPodcastDaniil Medvedev, who signed "Siuuu" on the camera, to Eurosport:"Break point, second serve and people are cheering like you already made a double fault - that's just disappointing ... it's not everybody who is doing it but those who are doing it probably have a low IQ." 5:01 PM · Jan 20, 202256855Daniil Medvedev, who signed "Siuuu" on the camera, to Eurosport:"Break point, second serve and people are cheering like you already made a double fault - that's just disappointing ... it's not everybody who is doing it but those who are doing it probably have a low IQ."💅 💅 https://t.co/43kXQ9mLHXDaniil Medvedev went one step further. After defeating Kyrgios to progress to the third round of the Australian Open, the Russian expressed his disappointment at the perpetrators, saying they possessed "low IQ".Fans on social media have also lamented the use of the chant, calling it outdated and annoying."Can confirm as someone who has been in John Cain Arena for about 5 hours these kids have been doing the Ronaldo “siuu” thing almost the entire time," ABC news reporter Heath Parkes-Hupton tweeted. "It was funny about 4 hours ago."Heath Parkes-Hupton@heath_parkesCan confirm as someone who has been in John Cain Arena for about 5 hours these kids have been doing the Ronaldo “siuu” thing almost the entire time. It was funny about 4 hours ago #AusOpen3:17 PM · Jan 18, 202214Can confirm as someone who has been in John Cain Arena for about 5 hours these kids have been doing the Ronaldo “siuu” thing almost the entire time. It was funny about 4 hours ago #AusOpenSKYE BLUE 🏴󠁧󠁢󠁳󠁣󠁴󠁿@13Rapha_LHope the Siuuu craze at the Australian Open sticks to the AO and doesn't spread to other tennis tournaments. Could be the worst variant yet.7:09 AM · Jan 20, 2022Hope the Siuuu craze at the Australian Open sticks to the AO and doesn't spread to other tennis tournaments. Could be the worst variant yet.Anukram Adhikary@AnukramAdhikaryWhat is this #Siu or #siuuu? The match between @DaniilMedwed and @NickKyrgios was full of it today at the @AustralianOpen. Quite disgraceful I must say at those in the crowd who were making those noises between serves and during his on-court interview too. Sassy #Medvedev is best7:00 AM · Jan 20, 2022What is this #Siu or #siuuu? The match between @DaniilMedwed and @NickKyrgios was full of it today at the @AustralianOpen. Quite disgraceful I must say at those in the crowd who were making those noises between serves and during his on-court interview too. Sassy #Medvedev is bestBen Way@BenWayAUSMaybe unpopular opinion, but I loved that sass from Daniil Medvedev. And the siuuu thing can get in the bin. #AustralianOpen4:54 AM · Jan 20, 2022956Maybe unpopular opinion, but I loved that sass from Daniil Medvedev. And the siuuu thing can get in the bin. #AustralianOpenDavid@Monsy723Though the crowd might be going 'SIUUU' instead of booing during Medvedev's chat with Courier, it doesn't make it any less cringe or disrespectful #AustralianOpen4:52 AM · Jan 20, 202214Though the crowd might be going 'SIUUU' instead of booing during Medvedev's chat with Courier, it doesn't make it any less cringe or disrespectful #AustralianOpenBoleyn Badger@bowlessoul@AustralianOpen @DaniilMedwed @NickKyrgios Tried watching this game. You can’t match Nick for entertainment value. But, I’m not putting up with that siuuu shit all night! I lasted a couple of minutes before turning back over to Murray v Taro 🤷🏻‍♂️1:52 AM · Jan 20, 20228@AustralianOpen @DaniilMedwed @NickKyrgios Tried watching this game. You can’t match Nick for entertainment value. But, I’m not putting up with that siuuu shit all night! I lasted a couple of minutes before turning back over to Murray v Taro 🤷🏻‍♂️Also Checkout : Rafael Nadal vs Roger Federer Head to Head Stats