adjective.
Marked by or acting with quiet, caution, and secrecy intended to avoid notice. synonym: secret.
The Century Dictionary and Cyclopedia
Acting by stealth; sly; secretive in act or manner; employing concealed methods: as, a stealthy foe; characterized by concealment; furtive: as, a stealthy proceeding; a stealthy movement.
the GNU version of the Collaborative International Dictionary of English
adjective.
Done by stealth; accomplished clandestinely; unperceived; secret; furtive; sly.
adjective.
Characterized by or resembling stealth or secrecy.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
marked by quiet and caution and secrecy; taking pains to avoid being observed
Word Usage
"My neighbor snowmobiles and a couple years ago had an encounter where the wolves had killed a deer on the trail and did not seem very afraid at all when they took off within sight. (and how stealthy is a group of snowmobiles?)"