onto: Meaning and Definition of

on•to

Pronunciation: (on't, ôn'- unstressed on't&schwa, ôn'-), [key]
— prep.
  1. to a place or position on; upon; on: to get onto a horse.
  2. in or into a state of awareness about: I'm onto your scheme.
—adj.
  1. pertaining to a function or map from one set to another set, the range of which is the entire second set.

onto-

Pronunciation: [key]
  1. a combining form meaning “being,” used in the formation of compound words: ontogeny.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.