Definition of "alter"

alter¹

/ˈɔːl.tə/

verb
third-person singular simple present alters, present participle altering, simple past and past participle altered
1. (transitive) To change the form or structure of.
  Quotations
  My covenant will I not break, nor alter the thing that is gone out of my lips.
  1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], Psalms 89:34
  No power in Venice can alter a decree.
  c. 1596–1598 (date written), William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act IV, scene i]
  It gilds all objects, but it alters none.
  1709, [Alexander Pope], An Essay on Criticism, London: […] W. Lewis […], published 1711
2. (intransitive) To become different.
3. (transitive) To tailor clothes to make them fit.
4. (transitive) To castrate, neuter or spay (a dog or other animal).
5. (transitive) To affect mentally, as by psychotropic drugs or illness.
  Quotations
  We don't know if he was altered on alcohol or drugs or anything […]
  2016 February 10, Sydney Pruitt and Claire Ricke (quoting Jeff Barrick), "Police: Man lying in street hit, killed by Capital Metro bus", KXAN

alter²

/ˈɔːl.tə/

noun
plural alters
1. An identity or headmate of a person with dissociative identity disorder (previously known as multiple personality disorder); a member of a system.
  Quotations
  While the second goal would be best met if each alter were coconscious, the defendant should be satisfied if at least one competent alter is present to hear what transpires.
  2000, Elyn R. Saks, ‎Stephen H. Behnke, Jekyll on Trial: Multiple Personality Disorder and Criminal Law (page 147)

alter³

/ˈɔːl.tə/

noun
1. Misspelling of altar.
  Quotations
  As an alter boy he remembered that walking between the alter and the gates was prohibited for everyone except the priest.
  2002, Nicholas Smeed, Resurrections: Vignettes About Discovery, Relationships, Personal Empowerment, And Preternatural Experiences, Xlibris Corporation, page 26
  The hardest part of being an alter boy was learning Latin. The mass was conducted in Latin and we had to learn to pray in Latin.
  2007, Jerry P. Martinez, Leche De Coyote, Xlibris Corporation, page 39
  On the alter, several candles sat unlit. An open bible rested among the candles. Behind the alter, hanging high, a huge cross was affixed to the wall, with a replica of Jesus in rags nailed to it. A simple wooden door stood closed behind the alter […]
  2009, Todd Sprague, Survive, Todd Sprague, page 142
  Truth motioned to Alexandra, “There; the key is kept on the alter.” She spotted it easily, for it was now well lighted by an amber colored presence light. She and the others moved quickly toward the alter.
  2011, Suzanne Dekeyzer James, The Stone Harp, Xlibris Corporation, page 146
  Third-rate alter boy. Skinny, lousy face, brown hair with a cowlick as big as Sputtnik. So as not to go on about it, I can put it in one word: Butt-ugly.
  2018, William Francis Jack, Alter Boy Rules, Lulu Press, Inc