mid-13c., "theft, action or practice of stealing," from Old English *stælþ, which is related to stelen (see steal (v.)), from Proto-Germanic *stælitho (cf. Old Norse stulþr), with Proto-Germanic abstract noun suffix *-itho (see -th (2)). Sense of "secret action" developed c.1300, but the word also retained its etymological sense into 18c. Got a boost as an adjective from stealth fighter, stealth bomber, radar-evading U.S. military aircraft, activated 1983.
Covert; clandestine; sneaky: His piece of stealth journalism was an exercise in character assassination/ The Republicans are turning Dan Quayle into a virtual stealth Vice President; not even any pictures of him on the Bush-Quayle re-election posters
[late 1980s+; fr the US Stealth fighter plane, activated in 1983, which, along with a bomber version, was designed to be invisible to radar detection]