Sam O’Donnell may not win this week’s Scripps National Spelling Bee in Washington, D.C., but it won’t be for lack of preparation.

Each contestant received study materials containing 18,000 words, and the 14-year-old eighth-grader from Ventura Missionary School has canvassed every entry, noting its root and origin. He used colored highlighters to track particularly vexing words so he could go back over them later.

The spelling words would stump many college English professors: devastavit, Lysenkoism, orfevrerie, gallipot, brunizem, eminentissimo, epideictic.

Beginning Wednesday, the curly haired older brother who is way into computers, Bart Simpson and alt-rock music will square off against 286 other champion spellers in the nation’s capital. Sam earned his spot by winning the Ventura County spelling bee in March.

The national winner will take home a $30,000 check, a savings bond, a college scholarship and instant fame from this supersized competition.

Sam’s goal is to make it to Thursday’s televised rounds, which start on ESPN and end in prime time on ABC for the second straight year. To get there, he has to excel Wednesday on a 25-word written test.

“Realistically, most of the words I get I probably won’t know,” he said last week from his upstairs bedroom in the family’s Ventura home, where he does most of his studying alone at his desk.

“I may have read the dictionary, but you can’t remember them all. It’s going to come down to whether or not I can figure it out.”

Handling the attention, cameras and unfamiliar faces will give him pause. But he plans to use his relative obscurity to his advantage.

Kendra Yoshinaga of Thousand Oaks represented Ventura County at the past three national bees and was considered a contender. Fifty-six competitors are returning spellers this year, including Samir Patel, who is back for a fifth year.

“I’m a total long shot, a nobody,” Sam said. “There’s less pressure that way.”

At Sam’s school on Foothill Road in Ventura, he’s a reluctant celebrity. Students strung banners and posters and taped up the newspaper article about his victory at the countywide bee.

“Everyone is really excited,” said his English teacher, Jeni Vargas. “Sam was a little overwhelmed and embarrassed by it.”

Vargas said Sam is off the charts when it comes to vocabulary. “But he doesn’t use it just to sound smart,” she said. “He uses the words appropriately.”

Sam, who wants to be a linguist or maybe a translator someday, said the weeks of intense studying actually have been “kind of fun.”

Sometimes he’d come home from school, start drilling words and not stop until bedtime.

The same week Sam turned 14, he got braces on his lower teeth to match his top row. “I can only eat mashed potatoes and soft foods,” he said. “Fortunately, I like mashed potatoes.”

When he’s not plowing through rare words, he’s usually updating his massive music collection. His computer contains more than 3,700 songs. Recent additions include Bjork, Arcade Fire, Gnarls Barkley and Massive Attack.

“Most of the kids in my school have never heard of these bands,” he said, pausing. “I kind of feel sorry for them.”

The purpose of the National Spelling Bee is to help students improve their spelling, increase their vocabularies, learn concepts and develop correct English usage that will help them all their lives. It is sponsored by the E. W. Scripps Co., parent company of the Ventura County Star.

Sam’s parents couldn’t be prouder. Yet despite his spelling prowess, his parents say they are most impressed that he has remained a well-rounded kid. He plays piano and tennis, he’s good to younger brother Danny, 11, and he doesn’t even want a cell phone.

“What he has already done is pretty amazing,” said his father, Paddy O’Donnell, a contractor. “To us, he’s already won.”