an expanded, dilated, or enlarged portion or form of a thing: The present article is an expansion of one he wrote last year.
anything spread out; expanse.
Mathematics.
the development at length of an expression indicated in a contracted form, as a2 + 2ab + b2 for the expression (a + b)2.
any mathematical series that converges to a function for specified values in the domain of the function, as 1 + x + x2 + … for 1/(1 − x) when x< 1.
Machinery. that part of the operation of an engine in which the volume of the working medium increases and its pressure decreases.
an increase in economic and industrial activity (opposed to contraction).
additional content for a video game, card game, board game, etc., that significantly expands or alters the way the game is played: I really improved my deck with cards from the latest expansion.You can play the stand-alone expansion without ever buying the original game.
Origin of expansion
1605–15; <Late Latin expānsiōn- (stem of expānsiō) a spreading out. See expanse, -ion
Still, the expansion in testing alone can’t fully explain the current case uptick, at least not in every country.
The new Covid-19 case surge in Europe, explained|Julia Belluz|September 17, 2020|Vox
China is a great nation, and we should hope for the continued expansion.
Trump’s most popular YouTube ad is a stew of manipulated video|Glenn Kessler, Meg Kelly|September 17, 2020|Washington Post
Many factors are driving the violent expansion of this years' wildfires.
West Coast wildfire smoke is visible from outer space|María Paula Rubiano A.|September 16, 2020|Popular Science
A few days later, Pfizer announced plans to expand the number of participants enrolled in its clinical trials by the thousands but gave little details on the expansion.
AstraZeneca resumed its COVID-19 vaccine trials after uncovering a mysterious reaction|Claire Maldarelli|September 15, 2020|Popular Science
In April, there was an hourlong “Election Administration Forum Conference Call” that covered, in part, the expansion of mail-in voting and “ways to message these concerns to your constituents,” according to the invitation.
No Democrats Allowed: A Conservative Lawyer Holds Secret Voter Fraud Meetings With State Election Officials|by Mike Spies, Jake Pearson and Jessica Huseman|September 15, 2020|ProPublica
He recently put up $50 million for half the cost of the Kennedy Center expansion, where he is chairman of the board.
Patriotic Philanthropy: Not an Oxymoron|Eleanor Clift|November 27, 2014|DAILY BEAST
He also has backed Medicaid expansion and a state-run exchange under Obamacare.
The Secret GOP Swing State Election Romp|John Avlon|October 28, 2014|DAILY BEAST
The era of expansion is over, to be replaced by an emphasis on ensuring the security of the existing members.
Did Vladimir Putin Just Save NATO?|Nico Hines|September 4, 2014|DAILY BEAST
Concerns about the proliferation of these labs date back to shortly after the expansion began in the early 2000s.
Growing Number of Biosafety Labs Raises Red Flags|Center for Public Integrity|August 20, 2014|DAILY BEAST
The Royal Navy, Zambellas said, “is seeing signs of expansion—which is a really weird place to be.”
Britain's High-Tech New Plan to Rule the Waves|Bill Sweetman|August 14, 2014|DAILY BEAST
Commerce, however, fixed Kinshassa as its base of operation, and its expansion has been astonishing for that part of the world.
An African Adventure|Isaac F. Marcosson
And—just as a guide for moments of expansion—might it be ‘Tony’?
What a Man Wills|Mrs. George de Horne Vaizey
Private enterprise must be given the greatest possible freedom to continue the expansion of economy.
State of the Union Addresses of Harry S. Truman|Harry S. Truman
The contour of the face expresses the most powerful command, and exalted, boundless, expansion of thought.
The Mirror of Literature, Amusement, and Instruction, No. 487|Various
A little distance above the island what appeared to be two rivers flowed into the expansion.
The Long Labrador Trail|Dillon Wallace
British Dictionary definitions for expansion
expansion
/ (ɪkˈspænʃən) /
noun
the act of expanding or the state of being expanded
something expanded; an expanded surface or part
the degree, extent, or amount by which something expands
an increase, enlargement, or development, esp in the activities of a company
maths
the form of an expression or function when it is written as the sum or product of its terms
the act or process of determining this expanded form
the part of an engine cycle in which the working fluid does useful work by increasing in volume
the increase in the dimensions of a body or substance when subjected to an increase in temperature, internal pressure, etc
An increase in the volume of a substance while its mass remains the same. Expansion is usually due to heating. When substances are heated, the molecular bonds between their particles are weakened, and the particles move faster, causing the substance to expand.
A number or other mathematical expression written in an extended form. For example, a2 + 2ab + b2 is the expansion of (a + b)2.