surreptitious /sur-əp-tishˈəs/

1. Done by stealth or fraud
2. Stealthy

surreptiˈtiously adverb

• climbing perch
• climbing perches
• climbings
• climbing wall
• climbing walls
• climbs
• climb the walls
• clime
• climes
• clinal
• clinamen
• clinamens
• clinch
• clinched
• clincher
• clincher-built
• clinchers
• clincher-work
• clincher-works
• clinches
• clinching
• clindamycin
• clindamycins
• cline
• clines