Pronunciation enPR: kăsträʹtō, IPA (key): /kæsˈtrɑː.təʊ/ Audio (UK)(file) Hyphenation: cas‧tra‧to Noun Singular castrato Plural castratos (countable) A castrato is a male soprano singer who has been castrated while still a boy to keep his voice high pitched. Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads