Etymology From Middle English varien, from Old French varier, from Latin variō (“to change, alter, make different”), from varius (“different, various”); see various.
He varies his magic tricks so as to minimize the possibility that any given audience member will see the same trick twice.
We are to vary the customs according to the time and country where the scene of action lies.1695, C[harles] A[lphonse] du Fresnoy, translated by John Dryden, De Arte Graphica. The Art of Painting, […], London: […] J[ohn] Heptinstall for W. Rogers, […], →OCLC:
2
To institute a change in, from a current state; to modify.
You should vary your diet. Eating just bread will do you harm in the end.
a. 1687, Edmund Waller, to Phyllis Gods, that never change their state, / Vary oft their love and hate.
3
Not to remain constant: to change with time or a similar parameter.
His mood varies by the hour.
The sine function varies between −1 and 1.
1 more example
[F]ear and anger, vvith alternate Grace, / Pant in her Breaſt, and vary in her Face!1712 (date written), [Joseph] Addison, Cato, a Tragedy. […], London: […] J[acob] Tonson, […], published 1713, →OCLC, Act III, scene i, page 44:
4
To display differences.
Of the members of a group
The sprouting tendency of potatoes varies between cultivars, years and places of growing.
In the new layout, it is proposed to provide three island platforms with six platform faces varying from 1,075 to 1,290 ft. in length and including bays.1960 February, “The modernisation of Peterborough”, in Trains Illustrated, page 108:
5
To be or act different from the usual.
I'm not comfortable with 3.Nc3 in the Caro-Kann, so I decided to vary and play exd5.
6
To make of different kinds; to make different from one another; to diversify; to variegate.
God hath[…] varied their inclinations.1650, Thomas Browne, Pseudodoxia Epidemica: […], 2nd edition, London: […] A[braham] Miller, for Edw[ard] Dod and Nath[aniel] Ekins, […], →OCLC:
God hath here / Varied his bounty so with new delights.1667, John Milton, “Book V”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, →OCLC:
7
Entertainment, Lifestyle, Music To embellish; to change fancifully; to present under new aspects, as of form, key, measure, etc. See variation.
8
Obsolete To disagree; to be at variance or in dissension.
the rich jewel which we vary for1623, John Webster, The Devil's Law Case:
Etymology From Middle English varien, from Old French varier, from Latin variō (“to change, alter, make different”), from varius (“different, various”); see various.
With euery gall, and varry of their Masters,c. 1603–1606, William Shakespeare, “The Tragedie of King Lear”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act II, scene ii]: