The word "prolifical" is spelled using the phonetic transcription /prəˈlɪfɪkəl/. The "pro-" prefix means "forward" or "in favor of", followed by the stem "life", and the suffix "-ical" meaning "having the character of". The word is not commonly used and may be considered archaic, with synonyms including "prolific", "productive", and "fruitful". The correct spelling may also be disputed due to its infrequency in modern usage.
Producing young or fruit in abundance; fruitful; productive.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.