1. Slyly and secretly
   "old line aristocratic diplomats underhandedly undermined the attempt...to align Germany with the Western democracies"
   - underhand

See also: underhand

• slipover
• slippage
• slipped disc
• slipper
• slipper orchid
• slipper plant
• slipper spurge
• slipper-shaped
• slippered
• slipperiness
• slipperwort
• slippery
• slippery dick
• slippery elm
• slippery slope
• slipping
• slippy
• slipshod
• slipskin grape
• slipstick
• slipstream
• slipway
• slit
• slit lamp
• slit trench