ownty-downty
/ˌəʊntɪˈdəʊnti/(also ownty-donty, owntsy-downtsy) US nursery and informal
adjective
= own pron.
Origin
Early 19th century; earliest use found in David Humphreys (1752–1818). Reduplication of own with variation of the initial consonant and suffixation, in imitation of childish speech.