The transitive verb to embiggen means to make bigger or greater, to enlarge.

This verb is frequently used humorously or ironically in recognition of its use as an invented word in the following from Lisa the Iconoclast, the sixteenth episode of the seventh series of the U.S. animated television series The Simpsons, first broadcast on Sunday 18^th February 1996:

Jebediah Springfield (in film): A noble spirit embiggens the smallest man…
Mrs. Krabappel: Embiggens? Hm, I never heard that word before I moved to Springfield.
Ms. Hoover: I don’t know why. It’s a perfectly cromulent word.

Bill Oakley credited Dan Greaney with the coinage of to embiggen in his commentary included in the 2005 DVD reissue of Series 7 of The Simpsons.

—Cf. also, from The Simpsons: cheese-eating surrender monkeys.

However, to embiggen was first coined to translate the ancient-Greek verb μεγαλύνειν, meaning to make great, magnify, as used in the Acts of the Apostles, 5:13.

The text in which to embiggen first occurred is the following reply, published in Notes and Queries: A Medium of Inter-Communication for Literary Men, General Readers, etc. (London, England) of Saturday 16^th August 1884 [6^th Series, Volume X, page 135/2]:

New Verbs (6^th S. ix. 469).—I am not going to try to settle the question started by Mr. Walford [note 1]. I believe it to be beyond the power of Prof. Skeat [note 2] or any other scholar or grammarian to settle what substantive, or even adjective, shall be turned into a verb when the many-mouthed beast takes it into its head to make one. Umpired, in the sense of a launch that carries the umpire, is assuredly not a good coinage. But is there much danger of its going beyond the boating slang of the river? I think not. Cricket has its slang; football has its slang; and lawn tennis has its genteel slang. But fresh slang coming up destroys old slang, and it is this we must look to, and not to grammarians, to rid the dictionaries of the jargon that “neweth every day.” [note 3] Are there not, however, barbarous verbs in all languages? ἀλλ᾽ ἐμεγάλυνεν αὐτοὺς ὁ λαός, but the people magnified them [note 4], to make great or embiggen, if we may invent an English parallel as ugly. After all, use is nearly everything.
C. A. Ward.
Haverstock Hill.

Notes:

1 C. A. Ward was replying to the following query by E. Walford, published in Notes and Queries: A Medium of Inter-Communication for Literary Men, General Readers, etc. (London, England) of Saturday 14^th June 1884 [6^th Series, Volume IX, page 469/1]:

New Verbs.—Will Prof. Skeat or some other English scholar and grammarian lay down a rule as to the extent to which writers may be allowed to carry the practice, which is alarmingly on the increase, of turning almost every known substantive into a verb? I note, for instance, an advertisement in the Times to the effect that “the launch that umpired the University boat race is to be let.” Now, I can quite admit the propriety of such words as to “cart” a load, to “post” a letter, to “stone” a mad dog, to “doctor” a patient, or even to “figure” a scene or event—these are admissible, and form part of our current language; but how can it be right to use the phrase to “umpire” instead of to “carry the umpire”? On this principle we shall soon have it said that an episcopal carriage “bishoped” Dr. A. or B., and that a government steam launch “admiraled” the Hyde or Cowes regatta.
E. Walford, M.A.
Hyde Park Mansions, N.W.

2 Walter William Skeat (1835-1912) was a British philologist.

3 “neweth every day” is a reference to the Prologue to Confessio Amantis, by the English poet John Gower (c.1330-1408):
—as printed by William Caxton in London in 1483:

Thus I whiche am a borell clerk
Purpose for to wryte a book
After the world that whylome toke
Long tyme in old dayes passyd
But for men seyn it is now lassed
In wers plyght than it was tho
I thenke for to touche also
The world whiche neweth euery daye

4 “but the people magnified them” translates “ἀλλ᾽ ἐμεγάλυνεν αὐτοὺς ὁ λαός” (Acts of the Apostles, 5:13) in the King James Bible (1611).