on·to | \ˈȯn-(ˌ)tü, ˈän-\

Definition of onto 

(Entry 1 of 2)

1 : to a position on We climbed onto the roof. Turn left onto Fifth Avenue.

2 : in or into a state of awareness about put me onto your methods was onto something that should have been pursued further— Bosley Crowther

3 used as a function word to indicate a set each element of which is the image of at least one element of another set a function mapping the set S onto the set T



Definition of onto (Entry 2 of 2)

: mapping elements in such a way that every element in one set is the image of at least one element in another set a function that is one-to-one and onto

Examples of onto in a Sentence


We climbed onto the building's roof. The book fell onto the floor. The water spilled onto the floor. The cowboy leaped onto his horse. Transfer the data onto a disk. Turn left onto Third Street at the traffic light.
See More

First Known Use of onto


1581, in the meaning defined at sense 1


1942, in the meaning defined above

Keep scrolling for more

Learn More about onto

Statistics for onto

Look-up Popularity

Time Traveler for onto

The first known use of onto was in 1581

See more words from the same year

Keep scrolling for more

More Definitions for onto

English Language Learners Definition of onto

: to a position that is on (something, such as a surface, area, or object)

: in a direction that allows you to get to or see (something)

—used to say that someone knows about what someone is doing or has done

on·to | \ˈȯn-(ˌ)tü, ˈän-\

Kids Definition of onto

: to a position on or against I leaped onto the horse.

Keep scrolling for more

More from Merriam-Webster on onto

Spanish Central: Translation of onto

Nglish: Translation of onto for Spanish Speakers

Britannica English: Translation of onto for Arabic Speakers

Comments on onto

What made you want to look up onto? Please tell us where you read or heard it (including the quote, if possible).


exaggeratedly or childishly emotional

Get Word of the Day daily email!

Test Your Vocabulary

Words from Greek and Roman Mythology Quiz

  • the-triumph-of-venus-by-alessandro-magnasco
  • Boreal comes from the name of the ancient Greek god of which wind?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Word Winder's CrossWinder

Test Your Knowledge - and learn some interesting things along the way.


Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!