PORTLAND, Ore. (AP) - Perhaps Barack Obama's competitive juices need new outlets now that he has expanded his lead over Democratic presidential rival Hillary Rodham Clinton.

On a five-hour flight from Washington to Oregon late Thursday, the Illinois senator came to the back of his charter plane for a spirited word game against reporters, and it was clear he did not intend to lose.

In "Taboo," a player under time constraints must prompt teammates to guess words or names without using obvious hints. For instance, in giving clues for "equator," the player is penalized if he says "Earth," "center" or "line."

Obama and a half-dozen aides took on a team of journalists, mostly young TV network reporters who have traveled with him for months. The senator jumped in eagerly and often.

When his communications director Robert Gibbs gave the clue, "I've got a good," Obama called out, "vibration!"

"Shorter than that," Gibbs said.

"Vibe," Obama guessed correctly.

Many clues touched on politics. Campaign aide Jen Psaki asked about something President Bush said on an aircraft carrier, and Obama quickly answered "mission accomplished." Close, but another aide and teammate, Reggie Love, later got the right answer: "mission control."

When Obama was giving clues, he ventured: "Thomas Jefferson called for it once in a while." Seeing the blank looks, he admitted, "that's too obscure." He then tried, "the Beatles did a song about it," and a teammate correctly answered, "Revolution."

Love, a former football and basketball player at Duke University, took a turn at giving clues, asking for a mall store "where gays go to buy clothes."

"Abercrombie and Fitch," answered Obama. Wrong. "The Gap," teammate Samantha Tubman correctly answered.

Obama fared no better when Tubman somewhat nervously gave clues for a type of men's and women's underwear. He incorrectly guessed "garters," while Love nailed it with "G-string."

The journalists fought back during their turns, sometimes tweaking the senator in the process.

"This is where Obama made his 'bitter' comments," ABC News reporter Sunlen Miller told her teammates, giving a clue for "California."

Obama winced at the mention of his much-criticized remarks about small-town residents clinging to guns and religion out of economic bitterness. "You dragged me back to the painful news," he said.

"Team Obama" won the first game, 26-17. As a second round went back and forth, Obama asked, "at what point is this game over?"

"When we win," a Bloomberg News reporter answered.

"That sounds familiar," Obama said, an obvious reference to Clinton's tenacity.

His team eked out a one-point victory, and the senator couldn't resist taunting the losers. "And you guys are professional wordsmiths!" he said as he headed back to his seat.