United States Slang

To have guts

guts (1): courage. "It took a lot of guts to ask his boss for a raise."

This expression replaces the earlier and now obsolete sense of stomach as “courage,” a usage from the early1500s. [; late 1800s ]

Scarf

Scarf down: to eat very quickly. “He always scarfs down his food."

1955-60, Americanism; variant of scoff (to eat voraciously.), with r inserted probably through r-dialect speakers' mistaking the underlying vowel as an r-less ar

Airhead

airhead: stupid person. "Believe it or not, Dave can sometimes act like an airhead!"

Probably used earlier than 1975-80.

Screw up

Screw up: to make a mistake. "I screwed up on the driving test, so I didn't pass.“

Origins aren’t clear.

Shades

shades: sunglasses. "Those are really cool shades.”

Shutter Shades were invented in the late 1940s, became a fad in the early 1980s and has experienced a revival in the early-to-mid 2010s. Instead of tinted lenses, they decrease sun exposure by means of a set of parallel, horizontal shutters (like a small window shutter).

Catch some rayscatch some rays: get some sunshine. "Let's go to the beach and catch some rays.“

Started being used in the second half of the 1900’s,

Bball

shoot some hoops: play basketball. "Let's shoot some hoops!“

Etymology: based on the basketball meaning of hoop (a high metal ring through which a ball is thrown to score points)

Cool

cool: excellent; superb. “English is totally cool!"

Slang use for "fashionable" is 1933, originally Black English, said to have been popularized in jazz circles by tenor saxophonist Lester Young.

Snookeredsnookered: cheated. "I got snookered into buying swamp land in Florida.“

1885-90; origin uncertain.

Couch potatocouch potato: a person who watches too much television. "Why did I have to marry such a couch potato?“

TV was called the boob-tube because it was thought to be for dumb people. So, people that watched it were called tubers. Tom Iacino used potato as a synonmyn for tuber and put couch in front of it since that’s where tubers sit (1976).

Geek

geek: someone who works too hard, is more intelligent than usual, and is typically but not always unattractive. "Bill Gates is kind of a geek.“

Perhaps a variant of geck "a fool, dupe, simpleton" (1510s), apparently from Dutch gek or Low German geck.

Specsspecs: eyeglasses. "I didn't know that you wore specs.“

Short for spectacles, 1807. 

Get itget it: to understand something. "Sorry, but I just don't get it."

Origins not found.

Sources

http://www.thefreedictionary.com

http://english.stackexchange.com

http://www.eslcafe.com

Images provided by Microsoft ppt.