unto vs. onto

preposition

  1. to (in its various uses, except as the accompaniment of the infinitive).
  2. until; till.


preposition

  1. to a place or position on; upon; on:

    to get onto a horse.

  2. Informal. in or into a state of awareness about:

    I'm onto your scheme.

adjective

  1. Also . Mathematics. pertaining to a function or map from one set to another set, the range of which is the entire second set.