1. In a disloyal and faithless manner
   "he behaved treacherously"
   - faithlessly, traitorously, treasonably, false

See also: treacherous

• fleetly
• fleetness
• Fleming
• Flemish
• Flemish dialect
• Flemish-speaking
• flense
• flesh
• flesh and blood
• flesh fly
• flesh out
• flesh wound
• flesh-colored
• flesh-coloured
• flesh-eating
• fleshed
• fleshed out
• fleshiness
• fleshly
• fleshpot
• fleshy
• FLETC
• fletch
• fletcher
• fleur-de-lis