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.
(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)
(phonetics, Sinosphere, often superscript) tone number 1, typically identified with dark level yinping (陰平). May simply be level ping tone (平) if the yin–yang distinction is not made.
(Internetslang,leetspeak,sarcastic)Deliberate misspelling of !, imitating someone who is too excited to consistently press the shift key while typing exclamation marks.
A: sum1 hlep me plz im alwyz l0zin!!1!?!/?
B: Thts bcuz ur st00pid!!!!!11!!oneone!!1!!eleven!1
Pronounced 幺 (yāo) when spelling phone number, one on dice or dominoes. This is similar to the English pronunciation of '0' as 'o' in strings of digits, such as 90210.