1

Tenth century “West Arabic” variation of the Nepali form of Hindu-Arabic numerals (compare Devanagari script १ (1, “éka”)), possibly influenced by Roman numeral Ⅰ, both ultimately from using a single stroke to represent the number one. See 1 § As a digit on WikipediaWikipedia for more.

1 (previous 0, next 2)

1. The cardinal number one, a single thing or unit.
2. A digit in decimal and every other base numbering system, including binary, octal, and hexadecimal.

   15 × 134 = 2010

   0010 0011₂ (the number 35 in binary notation)

   0x1000E001 (the number 268492801 in hexadecimal notation)

3. (mathematics) The identity element with respect to multiplication in a ring.

   a×1 = a

4. (computer science) Bit state corresponding to binary digit 1, or on or true.
5. (mathematics) A Boolean or truth value corresponding to true.

   f : B^k → B : B = {0, 1}

6. (mathematics) The one-point topological space, trivial ring, trivial group, a category with a single object or a (canonical) singleton.
7. (mathematics, set theory) indicator function of a set.
8. (phonetics, often superscript) the pitch of a tone, either high or low depending on local convention; '1' is most commonly the highest or lowest pitch (but see 0)

   Synonyms: ˥, ˩

9. (phonetics, Sinosphere, often superscript) tone number 1, typically identified with dark level yin ping (陰平). May simply be level ping tone (平) if the yin–yang distinction is not made.

   Synonym: ꜀

10. (linguistics, superscript) accent 1 in Norwegian, Swedish and Limburgish.

    Norwegian/Swedish toneme 1 is sometimes transcribed with a simple primary stress mark, that is ˈ.

The following forms are equivalent as a decimal digit:

The following additional forms are equivalent as a cardinal number:

• 1 (number) in Wikipedia
• (Arabic digits): 0 1 2 3 4 5 6 7 8 9

Other representations of 1:

• enPR: wŭn, IPA^(key): /wʌn/, IPA^(key): /wan/

• Audio (US)

  (file)

• Rhymes: -ʌn

1

1. (Internet slang, leetspeak, sarcastic) Deliberate misspelling of !, imitating someone who is too excited to consistently press the shift key while typing exclamation marks.

   Synonyms: one, eleven

   A: someone hlep me pls im always losing!!!1!

   B: Thats bcuz ur st00pid!!!!!11!!oneone!!1!!eleven!1

2. (rare, gaming) Abbreviation of one-shot or one-shotted.

1 (plural 1s)

1. (sports, skateboarding, snowboarding, skiing) Clipping of 180. (180° spin)

1

1. one
2. (gay slang) top

• (Hong Kong Cantonese) 1仔 (jat¹ zai²)

• 0 (líng)
• 0.5 (língdiǎnwǔ)

1

1. (text messaging) Abbreviation of ein.

1

1. (Should we delete⁽⁺⁾ this sense?) The number one (1).

   Synonyms: ett, en

2. (Internet slang, leetspeak, sarcastic) Deliberate misspelling of !

1

1. (nonstandard suffix) -et (“singular indefinite nominative; the”)

   Apotek1

   The Pharmacy

   Bud1

   The Courier

2. (nonstandard suffix) -et (“neuter singular”)

   Mog1 av dig.

   Very mature of you.

• mog1 (“mature”) (slang)