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. (Should we delete⁽⁺⁾ this sense?) The number one (1).
2. (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

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. 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)