Definition of superfetally in English:
superfetally
(also superfoetally)
adverb sjuːpəˈfiːt(ə)lisuːpəˈfiːtəlisuːpəˈfiːt(ə)li
rare Origin
Early 20th century; earliest use found in D'Arcy Wentworth Thompson (1860–1948), zoologist and classical scholar. From superfet- + -ally.