Learn how to say Stealthful correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word stealth:
1 [mass noun] cautious and surreptitious action or movement:
the silence and stealth of a hungry cat
privatization by stealth
2 [as modifier] (chiefly of aircraft) designed in accordance with technology which makes detection by radar or sonar difficult:
a stealth bomber
Middle English (in the sense ‘theft’): probably representing an Old English word related to steal, + -th2