IPA: /ˈzɑːrɛvɪtʃ/
KK: /tsɛrˈɛvɪtʃ/
The firstborn son of a Russian emperor, who is next in line to inherit the throne.
The czarevitch was trained from a young age to become the future ruler of Russia.
Czarevitch is derived from the Russian word "tsarevich" (царевич), which is a combination of "tsar" (цар) meaning "king" or "emperor" and the diminutive suffix "-evich" (евич) meaning "son of". Therefore, czarevitch refers to the son of a tsar, or a royal prince.
Think of a royal 'son' ('-evich') of a 'king' ('tsar') — that's what czarevitch means.