one of four children born at the same time from the same pregnancy
"The twins are now joined by a third sibling, making them part of a rare quad in their family."
a muscle of the thigh that extends the leg
"The surgeon examined the patient's quad to assess how well it could extend her leg after surgery."
a rectangular area surrounded on all sides by buildings
"The university quad is filled with students studying under the shade of old oak trees."
Four shots of espresso.
"The typesetter carefully inserted a quad between the columns of text to align them perfectly on the page."
A quadrangle (courtyard).
A quad bike (from quadricycle)
A blank metal block used to fill short lines of type.
In plain English: A quad is an open grassy area with trees and benches, usually found at schools or universities where students hang out to relax between classes.
"The new sports complex includes a quad with plenty of green space for students to relax between classes."
Usage: In modern usage, "quad" refers exclusively to the slang term for an Americano containing four shots of espresso; avoid using it as a noun or verb related to printing unless discussing historical typography contexts. Do not confuse this coffee drink with other multi-shot beverages like double lattes or triple espressos based on shot count alone.
to ride a quad bike
"The typesetter used metal spacers to quad out the irregular gaps between words on the printed page."
To fill spaces in a line of type with quads. Also quad out.
In plain English: To quad means to multiply something by four, making it twice as big again.
"The photographer will quad the image across four different screens for easy comparison."
Having four shots of espresso.
"After her injury, she spent weeks rehabilitating her quad muscles at the gym."
Of or relating to quads.
In plain English: Quad means having four parts, sections, or sides arranged together.
"The quad bike is perfect for driving through deep mud on a farm."
an informal strategic forum between the United States, Japan, Australia and India, focused on Asian security matters
"Leaders from the US, Japan, Australia, and India gathered at the quad summit to discuss regional security cooperation."
The word "quad" is a shortened form of several English words that ultimately derive from the Latin quattuor, meaning four. Its specific uses in typing and printing evolved separately, with the keyboard command coming from a verb sense while typography terms originated as abbreviations for an obsolete word called quadrat.