Definition of "mutable"

Vndoughtedly constaunce is an honourable vertue, as inconstance is reprochefull and odious. Wherfore that man whiche is mutable for euerye occasyon, muste nedes often repente hym, and in moche repentance is nat only moche foly, but also great detriment: whiche euery wyse man wyll eschue if he can.

1531, Thomas Elyot, “Of Constance or Stabilitie”, in The boke named the gouernour‎, book III, page e4v

For the mutable ranke-ſented Meynie, / Let them regard me, as I doe not flatter, / And therein behold themſelues.

c. 1608–1609 (date written), William Shakespeare, “The Tragedy of Coriolanus”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene i]

Maſters commands come with a power reſiſtleſs / To ſuch as owe them abſolute ſubjection; / And for a life who will not change his purpoſe? / (So mutable are all the ways of men) / Yet this be ſure, in nothing to comply / Scandalous or forbidden in our Law.

1671, John Milton, “Samson Agonistes, […]”, in Paradise Regain’d. A Poem. In IV Books. To which is Added, Samson Agonistes, London: […] J. M[acock] for John Starkey […], page 83, lines 415–420

It is in vain to interpose the explanation that the sonship was mutable. The Broad School do not say so ; and in so far they are consistent, for they recognise no power to produce the mutation.

1864, Rob S. Candlish, “The Fatherhood of God”, in The British and Foreign Evangelical Review, volume XIV, London: James Nisbet & Co., published 1865, page 748

A value of a mutable type can change. Objects and arrays are mutable: a JavaScript program can change the values of object properties and array elements. Numbers, booleans, null, and undefined are immutable.

2011, David Flanagan, JavaScript: The Definitive Guide

Hypothesis 6.14: Entropy levels within the social group may vary but must be maintained below maximum entropy on certain relevant variables (e.g., on the six globals and five mutables).

1990, Kenneth D. Bailey, Social Entropy Theory, page 281