stealth 
(stĕlth)
(stĕlth)n.
1. The act of moving, proceeding, or acting in a covert way.
2. The quality or characteristic of being furtive or covert.
3. Obsolete The act of stealing.
adj.
1. Not disclosing one's true ideology, affiliations, or positions: a stealth candidate.
2. Having or providing the ability to prevent detection by radar: a stealth bomber; stealth technology.
[Middle English stelth, probably from Old English *stǣlth.]