President Obama’s assertion that he does not need congressional authorization for the military operation in Libya met with criticism on Capitol Hill Thursday, as some lawmakers said Obama’s logic defied both the dictionary and the law.

“It just doesn’t pass the straight-face test in my view,” said House Speaker John A. Boehner (R-Ohio) in a morning news conference at the Capitol.

Much of the criticism focused on a single word, whose meaning is at the center of Obama’s case. The word is “hostilities.”

This is why it matters: Under a 1973 law, the War Powers Resolution, presidents must obtain Congress’s authorization when they insert U.S. forces into “hostilities.” That authorization must be obtained within 60 days — or 90 days, under certain circumstances.

In the Libyan operation, begun to protect civilians against the forces of Moammar Gaddafi, the 60-day deadline has already passed. The 90-day deadline is nearing.

Obama’s response, delivered Wednesday, was that the Libyan operation should not count as “hostilities.”

That, the administration said, is because there are no American ground troops in Libya, and because U.S. naval and air forces play largely supporting roles in a NATO-led operation. Remote-controlled U.S. drones have carried out some attacks on Gaddafi forces.

The report says that “because U.S. military operations [in Libya] are distinct from the kind of ‘hostilities’ contemplated by the resolution,” the deadlines do not apply.

On Capitol Hill Thursday, however, that argument did not seem to satisfy those who have been critical of Obama over the U.S. involvement in Libya.

“You’re flying over Libya, participating in bombing Libya. It seems hostile to me,” said Rep. Brad Sherman (D-Calif.), in a telephone interview. “If any other country were flying over the United States for the purpose of bombing our territory, we would regard that as being introduced into hostilities.”

Obama’s argument was rejected by Boehner, who previously had appeared intent on avoiding a confrontation over Libya until a number of Republicans and Democrats turned against the operation this month.

“The White House says there are no hostilities taking place, yet we’ve got drone attacks underway. We’re spending $10 million a day as part of an effort to drop bombs on Gaddafi’s compounds,” Boehner said.

Boehner said he still hoped to receive further clarification from the White House about the U.S.’s goals in Libya. Asked what the House is prepared to do in the case that it does not receive a satisfactory answer from Obama, Boehner declined to go into detail, saying only that “the House has options.”

In the Senate Thursday, even a major supporter of the Libya campaign made a speech criticizing Obama. Sen. John McCain (R-Ariz.) called the administration’s argument “a confusing breach of common sense.”

“I am no legal scholar, but I find it hard to swallow that U.S. armed forces dropping bombs and killing enemy personnel in a foreign country doesn’t amount to a state of hostilities,” McCain said on the Senate floor. “Unfortunately, this only adds more confusion to our already confusing policy in Libya.”

It also is unclear what will happen next in the Senate. That body is already considering one resolution that would support the Libyan operation, and another that would rebuke Obama for starting it without asking Congress first.

McCain said he would introduce another measure that offered explicit authorization for the use of limited force in Libya.

One of the few to publicly defend Obama was House Minority Leader Nancy Pelosi (D-Calif.). Pelosi said Thursday that she remains convinced that “the limited nature of this engagement allows the president to go forward.”

“I am satisfied that the president has the authority he needs to, and I say that as one very protective of congressional prerogative and very supportive of consultations” between the executive and legislative branches, Pelosi told reporters at a news conference.

Asked about Obama’s communications with Congress and the American public more broadly, Pelosi likened the relationship to that of a married couple.

“I always say to my colleagues, it’s like a marriage,” she said. “You may think you're communicating, but if the other party doesn’t think you’re communicating, you’re not communicating enough. So, think of it that way. You could always do more,” Pelosi said.