onto-

a combining form meaning “being,” used in the formation of compound words:

ontogeny.

Also, especially before a vowel, ont-.

Origin

< Neo-Latin < Greek ont- (stem of ón, neuter present participle of eînai to be) + -o- -o-

British Dictionary definitions for onto-

onto-

combining form

existence or being: ontogeny, ontology

Word Origin

from Late Greek, from ōn (stem ont-) being, present participle of einai to be

Word Origin and History for onto-

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).

onto- in Medicine

onto- or ont-
pref.
Organism; being: ontogeny.