• (RP) IPA: /ˈɔːl.tə/, /ˈɒl.tə/
• (GA) IPA: /ˈɔl.tɚ/
• (cot-caught, Canada) IPA: /ˈɑl.tɚ/

alter (alters, present participle altering; past and past participle altered)

1. (transitive) To change the form or structure of.
   • 1611, The Holy Bible, […] (King James Version), imprinted at London: By Robert Barker, […], OCLC 964384981 ↗, Psalms 89:34 ↗:

     My covenant will I not break, nor alter the thing that is gone out of my lips.

   • c. 1596–1598, William Shakespeare, “The Merchant of Venice”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: Printed by Isaac Iaggard, and Ed[ward] Blount, published 1623, OCLC 606515358 ↗, [Act IV, scene i]:

     No power in Venice can alter a decree.

   • 1709, [Alexander Pope], An Essay on Criticism, London: Printed for W. Lewis […], published 1711, OCLC 15810849 ↗:

     It gilds all objects, but it alters none.

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.
   • 2016 February 10, Sydney Pruitt and Claire Ricke (quoting Jeff Barrick), "Police: Man lying in street hit, killed by Capital Metro bus ↗", KXAN:

     We don't know if he was altered on alcohol or drugs or anything […]

• alteration
• alternate
• alternative

• German: abändern
• Portuguese: alterar, mudar, modificar
• Russian: изменя́ть
• Spanish: alterar, cambiar, modificar

alter (plural alters)

1. (especially, in the plural) One of the identities or personalities of a person with multiple personality disorder / dissociative identity disorder.
   • 2012, Robert J. Kohlenberg, ‎Mavis Tsai, Functional Analytic Psychotherapy (ISBN 0387708553):

     Often this process is highly aversive and evokes avoidance; that is, it can be very anxiety provoking to the host to be told that she is a multiple much less than to be told the details of an alter's experience. [...] She stated that she was now integrated, but that every day she meditated and visualized each of her alters[.]

alter (plural alters)

1. (proscribed) Alternative form of altar.
   • 2002, Nicholas Smeed, Resurrections: Vignettes About Discovery, Relationships, Personal Empowerment, And Preternatural Experiences, Xlibris Corporation (ISBN 9781462800490), page 26:

     As an alter boy he remembered that walking between the alter and the gates was prohibited for everyone except the priest.

   • 2007, Jerry P. Martinez, Leche De Coyote, Xlibris Corporation (ISBN 9781469118307), page 39:

     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.

   • 2009, Todd Sprague, Survive, Todd Sprague (ISBN 9781448685776), page 142:

     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 […]

   • 2011, Suzanne Dekeyzer James, The Stone Harp, Xlibris Corporation (ISBN 9781456843328), page 146:

     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.

   • 2018, William Francis Jack, Alter Boy Rules, Lulu Press, Inc (ISBN 9780359140015)

     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.