Definition of identity in English:

identity

Line breaks: iden|tity
Pronunciation: /ʌɪˈdɛntɪti
 
/

noun (plural identities)

  • 1The fact of being who or what a person or thing is: he knows the identity of the bombers [mass noun]: she believes she is the victim of mistaken identity
    More example sentences
    • In fact, her identity as a citizen in urban India is one that is minimally developed, if at all.
    • It doesn't matter that the joke is about mistaken identity or the fact that they're chasing the wrong vehicle - Atkinson can make you laugh at it anyway.
    • Being one of the king's personal guests had given them a special status despite the fact that their identities had yet to be given.
    Synonyms
  • 1.1The characteristics determining who or what a person or thing is: he wanted to develop a more distinctive Scottish Tory identity
    More example sentences
    • That is, what about people who deliberately disrupt the continuity that ordinarily characterizes our identity?
    • My appreciation of this country stems from the fact that our national identity is impossible to pin down.
    • What should be one of the most important facts of our national identity is instead one of the government's most closely guarded secrets!
    Synonyms
    individuality, self, selfhood, ego, personality, character, originality, distinctiveness, distinction, singularity, peculiarity, uniqueness, differentness
  • 1.2 [as modifier] (Of an object) serving to establish who the holder, owner, or wearer is by bearing their name and often other details such as a signature or photograph: an identity card
    More example sentences
    • Tickets issued at student fares are only valid for travel in conjunction with a valid student identity card bearing a photograph of the holder.
    • Young people across South Lakeland and Furness are being encouraged by police to carry photograph identity cards to prove their age.
    • All candidates were expected to have identity cards bearing their photographs to prevent other people sitting examinations for them.
  • 3 Mathematics (also identity operation) A transformation that leaves an object unchanged.
    More example sentences
    • Any object, indeed any molecule, will contain at least one of these symmetry elements - the operation C 1 known as the identity operation - a rotation of 360°, the equivalent of doing nothing.
    • The table gives the result of all possible pairwise combinations of the four operations I, R, P and Y (which stand for the identity operation and for 180-degree rotations around the roll, pitch and yaw axes).
  • 3.1 (also identity element) An element of a set which, if combined with another element by a specified binary operation, leaves that element unchanged.
    More example sentences
    • Group theory studies not a single structure, but a type of structure, the pattern common to collections of objects with a binary operation, an identity element thereon, and inverses for each element.
    • First, among the operations there must be an identity element - an operation that leaves the system unchanged.
    • For example, the collection of integers under addition is a group (the identity element is 0), and groups occur throughout mathematics from geometry to combinatorics to cryptography.
  • 4 Mathematics The equality of two expressions for all values of the quantities expressed by letters, or an equation expressing this, e.g. (x + 1)2 = x2 + 2x + 1.
    More example sentences
    • Identity and equality are two fundamental binary relations which relate expressions of a given type.

Origin

late 16th century (in the sense 'quality of being identical'): from late Latin identitas, from Latin idem 'same'.

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