The term 'first actually reduced to practice' can be replaced with several synonyms, including 'initial implementation', 'early execution', or 'primary demonstration'. These words convey the same meaning as the original phrase, indicating the first time an idea or concept was put into action. Other alternatives include 'pioneer implementation', 'inaugural execution', or 'introductory demonstration'. Using synonyms in writing or speech can add variety and nuance to language, making it more dynamic and engaging. Familiarizing oneself with a range of synonyms can help to avoid repetitive language and expand one's vocabulary.