An upset occurs in a competition, frequently in electoral politics or sports, when the party popularly expected to win (the favorite), is defeated by an underdog whom the majority expects to lose, defying the conventional wisdom. The underdog then becomes a giant-killer.

The meaning of the word has popularly been attributed to the surprising defeat of the horse Man o' War by the horse Upset (the loss was the only one in Man o' War's career, though Man o' War later defeated Upset), though the term pre-dates that 1919 race.

In 2002, George Thompson, a lexicographic researcher, used the full-text online search capabilities of the New York Times databases to trace the usage of the verb to upset and the noun upset. The latter was seen in usage as early as 1877. Thompson's research debunked one popular theory of the term's origin, namely that it was first used after the Thoroughbred racehorse Upset became the only horse to defeat the legendary Man o' War in 1919.

The meaning of the word "upset" has long included "an overthrowing or overturn of ideas, plans, etc." (see OED definition 6b), from which the sports definition almost surely derived. "Upset" also once referred to "a curved part of a bridle-bit, fitting over the tongue of the horse," and though the modern sports meaning of "upset" was first used far more for horse races than for any other competition, there is no evidence of a connection. The name of the horse "Upset" came from the "trouble" or "distress" meaning of word (as shown by the parallelism of the name of Upset's stablemate, Regret).

Yuvan Shankar Raja (Tamil: யுவன் சங்கர் ராஜா; born 31 August 1979) is a Tamil film score and soundtrack composer, singer and occasional lyricist. He has predominantly scored music for Tamil as well as several Telugu films. His musical career began in 1996, at age 16, as he composed the film score for Aravindhan. After initial struggle, he made his big break with the Thulluvadho Ilamai soundtrack (2001), and evolved as one of Tamil cinema's most sought-after composers by the mid-2000s.

Within a span of 14 years, Yuvan Shankar Raja worked on over 85 films. Considered a versatile composer, he often strives for different and innovative music and has explored and used elements of various genres in his compositions that range from folk to heavy metal. He is particularly known for his use of western music elements in his pieces and often credited with having introduced Hip hop to the Tamil film and music industry and having started the "era of remixes" in Tamil Nadu. Being immensely popular among the younger generation, he is frequently referred to as the "Rockstar", and the "Youth Icon of Tamil Film Music". In addition, Yuvan Shankar Raja is recognized for his background score in films (re-recording) that have fetched him accolades among critics.