algorithm

• algorism (obsolete)
• augrim (obsolete)

From Middle English algorisme, augrym, from Anglo-Norman algorisme, augrim, from Medieval Latin algorismus, from Arabic الخَوَارِزْمِيّ (al-ḵawārizmiyy), the nisba of Persian mathematician Muḥammad ibn Mūsā al-Khwārizmī and a toponymic name meaning "person from Chorasmia". The spelling change (-s- > -th-) was influenced by unrelated Ancient Greek ἀριθμός (arithmós) (whence English arithmo-).[1]

• (Received Pronunciation) enPR: ălʹgə-rĭ-thəm, ălʹgə-rĭth-m, IPA^(key): /ˈælɡəɹɪðəm/, [ˈæɫɡəɹɪðm̩]
• (General American) enPR: ălʹgə-rĭ'thəm, ălʹgə-rĭth'm, IPA^(key): /ˈælɡəˌɹɪðəm/, [ˈæɫɡəˌɹɪðm̩]

• Audio (US)

  (file)

• Hyphenation UK: al‧gorithm, US: al‧go‧rithm

algorithm (countable and uncountable, plural algorithms)

1. (countable) A collection of ordered steps that solve a mathematical problem. A precise step-by-step plan for a computational procedure that possibly begins with an input value and yields an output value in a finite number of steps.
   • 1990, Cormen, Leiserson, and Rivest, Introduction to Algorithms: page 1. Cambridge, MA, The MIT Press, 1999 (23rd printing)

     Informally, an algorithm is any well-defined computational procedure that takes some value, or set of values, as input and produces some value, or set of values, as output. An algorithm is thus a sequence of computational steps that transform the input into the output.

   • 2010, Aaron Sorkin, The Social Network:

     Mark Zuckerberg: No, I need the algorithm you used to rank chess players. / Eduardo Saverin: Are you OK? / Mark Zuckerberg: We're ranking girls.

   • 2013 July 26, Leo Hickman, “How algorithms rule the world”, in The Guardian Weekly‎, volume 189, number 7, page 26:

     The use of algorithms in policing is one example of their increasing influence on our lives. And, as their ubiquity spreads, so too does the debate around whether we should allow ourselves to become so reliant on them – and who, if anyone, is policing their use.

   • 2018 June 25, Sam Jones, “Ex-Nato chief refused visa waiver to US because of Iran trips”, in The Guardian:

     It’s a computer – an algorithm – and if you’ve been in Iran lately, they take you out of the system.

2. (loosely) A flowchart illustrating a decision-making process for human users, especially health care professionals.
   • 2023, Lee SG, Blood AJ, Cannon CP, Gordon WJ, Nichols H, Zelle D, Scirica BM, Fisher NDL, “Remote cardiovascular hypertension program enhanced blood pressure control during the COVID-19 pandemic”, in J Am Heart Assoc, volume 12, number 6, →DOI, →PMID, page e027296:

     This retrospective observational analysis evaluated BP [blood pressure] control in an entirely remote management program before and during the pandemic. A team of pharmacists, nurse practitioners, physicians, and nonlicensed navigators used an evidence‐based clinical algorithm to optimize hypertensive treatment. The algorithm was adapted during the pandemic to simplify BP control.

3. (uncountable, obsolete) Calculation with Arabic numerals; algorism.
4. (informal, social media, by extension, usually preceded with "the") The recommendation algorithm used by social media websites to determine the contents of one's feed.
   • 2018 February 26, Tad Friend, quoting Donald Glover, “Donald Glover Can’t Save You”, in The New Yorker‎:

     Glover began his acceptance speech by saying, “First, I want to thank the algorithm that put us all here.”

• pseudoalgorithm

• → Japanese: アルゴリズム (arugorizumu)
• → Korean: 알고리즘 (algorijeum)

• logarithm, mithralog