on·to
ˈȯn-(ˌ)tü
ˈän-
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
: 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
Cite this Entry
“Onto.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/onto. Accessed 7 Sep. 2026.
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