The Siuuu is Cristiano Ronaldo's signature goal celebration, performed with a mid-air spin and landing with arms spread as he shouts the word. It became familiar worldwide through televised football matches and fan videos, with crowds in stadiums copying the shout after goals. On social media it spread far beyond football, becoming a shorthand for triumph, confidence and playful bragging in edits, reaction videos and short-form clips. Its simplicity and instantly recognisable sound keep it in regular use years after it first became famous.