superfetally
/suːpəˈfiːt(ə)li/ /sjuːpəˈfiːt(ə)li/ /suːpəˈfiːtəli/(also superfoetally) rare
adverb
By superfetation.
Origin
Early 20th century; earliest use found in D'Arcy Wentworth Thompson (1860–1948), zoologist and classical scholar. From superfet- + -ally.