The 13-year-old from West Lafayette, Indiana, who often had the audience laughing with his one-line commentaries, was all business when he aced "guerdon"-a word that appropriately means "something that one has earned or gained"-to win the 81st version of the bee.
"I don't know about comedy lines, but my parents have been telling me since the beginning that I should always stay calm, cool and collected," said Sameer, who likes playing the violin and video games, and hopes one day to be a neurosurgeon.
Sameer, appearing in the bee for the fourth time and a top 20 finisher the last two years, clenched both fists and put his hands to his face after spelling the winning word.
He won a tense duel over first-time participant Sidharth Chand, 12, of Bloomfield Hills, Michigan, who finally stumbled on "prosopopoeia," a word describing a type of figure of speech.
Sameer is coached by his sister, Shruti, a high school senior and three-time spelling bee competitor. He was a crowd favorite throughout the tournament. The first-place finish won him US$35,000 in cash and more than US$5,000 in other prizes.