Mid 19th century; earliest use found in Robert Montgomery (1807–1855), poet and Church of England clergyman. From ontology + -ize, after German ontologisieren.
Definition of ontologize in US English:
ontologize
(also ontologise)
verbɒnˈtɒlədʒʌɪz
1no objectTo apply or deal with ontology.
2with objectTo treat ontologically.
Origin
Mid 19th century; earliest use found in Robert Montgomery (1807–1855), poet and Church of England clergyman. From ontology + -ize, after German ontologisieren.