Upon; on top of. / (informal) Aware of. / (mathematics) Being an onto function with a codomain of (see below).

(mathematics, of a function) Assuming each of the values in its codomain; having its range equal to its codomain.

being

A light, armored anti-tank vehicle of a particular kind.

Alternative spelling of Ontos

Alternative form of be on to

(idiomatic, transitive) To obtain, acquire or get and keep hold of something.

(transitive) To reverse a vehicle onto something. / (transitive) To overlook something from the rear.

To contact a person or organisation about a particular matter. / To connect, especially to the Internet or a network. / (transitive) To scold someone.

to keep