on•toPronunciation: (on'tOO, ôn'-; unstressed on'tu, ôn'-), [key]
to a place or position on; upon; on: to get onto a horse.
in or into a state of awareness about: I'm onto your scheme.
pertaining to a function or map from one set to another set, the range of which is the entire second set.
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.