a word in philosophy, variously defined but in general "pertaining to the existence of structure in an entity," 1949, from onto- + -ic.
Entries linking to ontic
onto-
word-forming element meaning "a being, individual; being, existence," from stem of Greek on (genitive ontos) "being," neuter present participle of einai "to be" (from PIE root *es- "to be").
-ic
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.