• (British) IPA: /ˈɒn.tuː/
    • (America) IPA: /ˈɑn.tu/
  • (unstressed) IPA: /ˈɒn.tə/
  • (unstressed) IPA: /ˈɒn.tʊ/
  1. Upon; on top of.
    My cat just jumped onto the keyboard.
  2. (informal) Aware of.
    The thought-police were onto my plans of world domination.
  3. (mathematics) Being an onto function with a codomain of (see below).
    The exponential function maps the set of real numbers onto the set of positive real numbers.
Translations Adjective

onto (not comparable)

  1. (mathematics, of a function) Assuming each of the values in its codomain; having its range equal to its codomain.
    Considered as a function on the real numbers, the exponential function is not onto.

Offline English dictionary