WASHINGTON – Sean Conley studied nearly half his life for the chance to be America’s best speller, practicing 20,000 words. He needed 16 on Thursday to win the National Spelling Bee.

He plowed through “tropophilous,” “schadenfreude,” “aleatoric” and “epexegesis.”

“I guess all that practice really paid off this time,” the 13-year-old from Shakopee, Minn., said after outspelling 247 others in three marathon days of competition.

His winning word was “succedaneum,” which means, appropriately, “one that succeeds to the place of another.” Sean, the first runner-up in last year’s Scripps Howard spelling bee, handled it with no trouble and allowed himself only a small smile in accepting the trophy.

Sean had gone word-for-word for five breathless rounds with Kristin Hawkins, a soft-spoken Virginia eighth-grader who, like Sean, was participating in the national bee for the third time.

Kristin rattled off such words as “hamartia” as if she were spelling her own last name. The word means “a defect of character.”

But then she stumbled over “resipiscence,” meaning a change of mind or heart.

Sean will take home $10,000, while Kristin will get $5,000.

Rebecca Garthoff, who represented the Bangor Daily News and was the only speller from Maine at the 74th annual competition, fell in the third round on “orchidaceous.”

By the end of the fourth round, the original group of 248 spellers had shrunk to 34. Sean won in the 16th round.

He almost didn’t make it out of the fourth round himself, grappling for several minutes with “inesculent,” which means “inedible.” He wrote the word in the air and with his finger on his name placard nearly a dozen times. He reluctantly began spelling when pressed by the judges. Later, the quiet eighth-grader said it was the hardest word he faced and that the air-writing helps when “I can’t see the whole thing in my head.”

The final rounds pitted spellers familiar with each other.

Joy Nyenhuis-Rouch, a West Lafayette, Ind., eighth-grader making her fourth appearance, was eliminated in the ninth round after missing “alkyd,” referring to a group of plastics. Also eliminated in that round was Michael Hessenauer, 13, of Dublin, Ohio, who tied for fifth last year. He was caught by “cancelli,” church partitions.

It probably didn’t help that the final day of competition was broadcast on live TV. In fact, as soon as the broadcast began, the first seven students misspelled their words.

The group included diminutive Sara Brand, 11, a sixth-grader from Knoxville, Tenn., who mulled over “Australopithecus” for so long the judges asked that she please get to the spelling. She began it with an “O” and never recovered.

A few minutes later, Abhijith Eswarappa, 13, of Memphis, Tenn., broke the losing streak by carefully spelling “fimbrillate,” a word meaning “bordered with a minute fringe.”

Eve Vokes, a fifth-grader from San Antonio, Texas, her blonde hair pulled back into tight, matching braids, stared at the judges, her hands pinned behind her, as she puzzled over “nisei,” an American-born Japanese person. She spelled it “nesae.”