alter

Etymology 1

From Old French alterer (French altérer), from Medieval Latin alterāre (“to make other”), from Latin alter (“the other”), from al- (seen in alius (“other”), alienus (“of another”), etc.; see alias, alien, etc.) + compar. suffix -ter.

verb

1. (transitive) To change the form or structure of.
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.
   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

Etymology 2

Probably from alter ego.

noun

1. (especially in the plural) An identity or headmate of a person with dissociative identity disorder (previously known as multiple personality disorder); a member of a system.

Etymology 3

noun

1. Misspelling of altar.
   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