World War II gave us many political, social, economic and technological advances. But it also left its imprint on our language.

It gave birth to "snafu," an acronym for an R-rated phrase that describes a situation in characteristic disorder. The small four-wheel-drive vehicles used in the war never lost the name "jeep." Portable two-way radios would forever be known by the more colorful label "walkie-talkies." And, on a darker note, one of the most horrific chapters of the 20th century gave extermination a new name: genocide.

"Wars always leave their mark on the vocabulary as well as the citizens," said Joan Houston Hall, chief editor of the Dictionary of American Regional English. "Sometimes, they introduce new words that immediately take hold. Other times, they introduce words that are prominent and [then] fall out of use. And still other times, they take words that have been in the language and have not been prominent, and they make them prominent."

Paul Dickson, an author of several books on language, including "War Slang: American Fighting Words and Phrases Since the Civil War," said World War II has had the biggest linguistic impact of any U.S. war. "World War II really changed the way we talked," Dickson said.

The reason, he and other experts said, was that the U.S. armed forces were made up mostly of citizen-soldiers -- average men from different economic, regional and ethnic backgrounds whose speech was unvarnished and often cleverly funny. Their way with words was uniquely American, emphasizing simple descriptions over puffy jargon.

"The language became much more informal, much slangier," said Dickson, who lives in Garrett Park. "The average guy was seeing things whimsically."

For a 1994 book on military slang, Dickson researched terms that either were coined during World War II or became much more widespread during the war. Though some of the words have fallen out of favor -- few people today would say they are "in the gravy" to describe being in comfortable circumstances -- dozens of others still turn up regularly in conversation.

"Gung-ho" was the motto Lt. Col. E.F. Carlson gave his Marine Raiders. "Blitzkrieg" was German for a sudden, swift attack before its shortened version gained popularity on the football field. A "dry run" was military slang for something done for practice only.

According to the U.S. Army Center of Military History, the term "D-Day" describes the day on which a combat attack is to be initiated. The earliest use of "D-Day," the center found, came during World War I, with a 1918 field order. But it was during World War II and the invasion of Normandy on June 6, 1944, that D-Day became cemented in the popular culture, Dickson said.

"GI" once stood for "government issue" and described equipment and materials used by members of the armed forces, as in "GI soap." But in the last half of the war, the use of "GI" to refer to the soldiers themselves began to take hold, said Christine Ammer, a lexicographer and author of "Fighting Words: From War, Rebellion, and Other Combative Capers."

"Sweat it out," meaning to endure, was strictly a Southern expression before the war, but during the war "it got picked up and spread around," said Jesse Sheidlower, principal editor of the American office of the Oxford English Dictionary.

America's recent conflicts in Afghanistan and Iraq have introduced or popularized several words, such as "embedded," but Sheidlower and other experts said it's impossible to predict which ones will resonate in years to come.