The spelling of number is number, but the abbreviation is No (№). There is no letter o in number, so where does this spelling come from?

  • @MετάEd Very good. Why don't you supply those two comments as an answer?
    – WS2
    Apr 5, 2016 at 17:37

1 Answer 1


No (frequently stylized ) is the abbreviation for Latin: numero (in number). It’s used even though the word being abbreviated is English: number. Other examples of this practice:

  • lb, abbreviation of Latin: libra (balance) – used as abbrevation for English: pound

  • &, a stylized way to write Latin: et (and) – used as abbreviation for English: and

Why? These Latinate abbreviations were second nature to educated people who wrote in Latin. When they wrote in English, they carried these abbreviations over to the “new” language.

  • 1
    Except that the Latin for "number" is numerus, not numero. This unexplained explanation is repeated until it is indistinguishable from folk etymology. Nonetheless, I believe it is correct, and leave it as an exercise for an interest party to explain.
    – deadrat
    Apr 6, 2016 at 6:35
  • 4
    @deadrat In Latin, "numero" means "with the number", so you could say No. 10 Downing Street ought to be literally translated "Building With The Number Ten On Downing Street". But we don't bother with ablative case in English, and would just say Building Number Ten. So "number" is in fact the English equivalent for "numero".
    – MetaEd
    Apr 6, 2016 at 16:35
  • 1
    Nice try, but no.
    – deadrat
    Apr 6, 2016 at 17:25
  • 2
    @deadrat My opinions may change, but never the fact that I am right.
    – MetaEd
    Apr 6, 2016 at 17:37
  • 1
    Your opinion about whether you're right certainly seems immutable. Nevertheless your explanation of the abbreviation is wrong. Which is the immovable object and which is the irresistible force? A bonus point for ablative though.
    – deadrat
    Apr 6, 2016 at 22:12

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