The Word is:”one”

one

/wʌn/
number
cardinal number: one; adjective: one; noun: one; adverb: one

1. the lowest cardinal number; half of two; 1.
“there’s only room for one person”

  • a single person or thing.
    plural noun: ones
    “they would straggle home in ones and twos”
    synonyms: a single, a solitary, a sole, a lone
    “only one person came”
  • just one as opposed to any more or to none at all; single (used for emphasis).
    “her one concern is to save her daughter”
    synonyms: only, single, solitary, sole
    “her one concern was her daughter”
  • denoting a particular item of a pair or number of items.
    “electronics is one of his hobbies”
  • denoting a particular but unspecified occasion or period.
    determiner: one
    “one afternoon in late October”
    synonyms: some, any, a certain
    “one day they’ll come”
  • used before a name to denote a person who is not known to the reader or hearer; a certain.
    “he worked as a clerk for one Mr Ming”
  • North Americaninformal
    a noteworthy example of (used for emphasis).
    “the actor was one smart-mouthed troublemaker”
  • one year old.
  • one o’clock.
  • “I’ll be there at one”

  • a size of garment or other merchandise denoted by one.
    plural noun: ones
  • a domino or dice with one spot.
  • 2. the same; identical.
    “all types of training meet one common standard”
    synonyms: only, single, solitary, sole
    “her one concern was her daughter”
    3. informal
    a joke or story.
    “the one about the Englishman, the Irishman, and the Yank”
    4. informal
    an alcoholic drink.
    “a cool one after a day on the water”
    5. West Indian
    alone.
    “the time when you one tackled a field of cane and finished before the others had even started”

    pronoun

    pronoun: one

    1. referring to a person or thing previously mentioned or easily identified.
    “her mood changed from one of moroseness to one of joy”
    2. a person of a specified kind.
    “you’re the one who ruined her life”
    a person who is remarkable in some way.
    “you never saw such a one for figures”
    3. used to refer to the speaker, or any person, as representing people in general.
    “one must admire him for his willingness”

    Source credit: Google