Try Our Apps


The Best Internet Slang


[on-too, awn-; unstressed on-tuh, awn-] /ˈɒn tu, ˈɔn-; unstressed ˈɒn tə, ˈɔn-/
to a place or position on; upon; on:
to get onto a horse.
Informal. in or into a state of awareness about:
I'm onto your scheme.
Also, surjective. Mathematics. pertaining to a function or map from one set to another set, the range of which is the entire second set.
Origin of onto
First recorded in 1575-85; on + to
Can be confused
on, onto, on to.


a combining form meaning “being,” used in the formation of compound words:
Also, especially before a vowel, ont-.
< New Latin < Greek ont- (stem of ón, neuter present participle of eînai to be) + -o- -o- Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2017.
Cite This Source
Examples from the Web for onto
Contemporary Examples
Historical Examples
  • He tossed them onto the table, and Hal Dozier rolled his smoke in silence.

    Way of the Lawless Max Brand
  • If you'd been onto your job, things would have been smooth as silk.

    Chip, of the Flying U B. M. Bower
  • But it must be something new, or we should have got onto it.

    It Happened in Egypt C. N. Williamson
  • With a word of farewell, he climbed out of the cockpit and onto a wing.

    The Solar Magnet Sterner St. Paul Meek
  • I can mention his name now without Ketury's landin' onto me like a snowslide.

    Cy Whittaker's Place Joseph C. Lincoln
British Dictionary definitions for onto


/ˈɒntʊ; unstressed ˈɒntə/
to a position that is on: step onto the train as it passes
having become aware of (something illicit or secret): the police are onto us
into contact with: get onto the factory
Usage note
Onto is now generally accepted as a word in its own right. On to is still used, however, where on is considered to be part of the verb: he moved on to a different town as contrasted with he jumped onto the stage


combining form
existence or being: ontogeny, ontology
Word Origin
from Late Greek, from ōn (stem ont-) being, present participle of einai to be
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for onto

1580s, as on to, from on + to. Appeared much later than parallel into. As a closed compound (on analogy of into), first recorded 1715.


word-forming element meaning "a being, individual; being, existence," from Greek onto-, from stem of on (genitive ontos) "being," neuter present participle of einai "to be" (see essence).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
onto in Medicine

onto- or ont-
Organism; being: ontogeny.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Difficulty index for onto

Most English speakers likely know this word

Word Value for onto

Scrabble Words With Friends

Nearby words for onto