n.

1. 身份；本身；本体[C][U]
   His driver's license revealed his identity.

   他的驾驶执照证明了他的身份。

2. 同一人；同一物[U]
   The experts established the identity of the bronze bell with one described in an old document.

   专家们确定这口青铜钟就是一份古文献中所描述的那口。

3. 同一（性）；相同（处），一致（处）[U][C]
   The identity of the fingerprints on the gun proved that he was the killer.

   留在枪上的指纹证实他就是杀人者。

   Identity of interests is the bond that unites them.

   利害的一致是把他们联合起来的纽带。

4. 个性，特性[C][U]
   preserve the distinct identities of an old town

   保留古镇的特有风貌

n.

1. the fact of being who or what a person or thing is.
   ▸the characteristics determining this.
   ▸ [as modifier] serving to establish the identity of the owner:

   an identity card.
2. a close similarity or affinity.
3. Mathematics  (also identity operation) a transformation that leaves an object unchanged.
   ▸ (also identity element) an element of a set which, if combined with another element, leaves that element unchanged.
4. Mathematics  an equation expressing the equality of two expressions for all values of the variables, e.g. (x + 1)² = x² + 2x + 1.