1. Lacking official approval
   - unaccredited, unlicensed

See also: unauthorised [Brit], unauthorized

• slowness
• slowpoke
• slowworm
• SLR
• SLS
• slub
• slubbed
• slubber
• slubberdegullion
• sludge
• sludgy
• slue
• slug
• slugabed
• slugfest
• sluggard
• slugger
• sluggish
• sluggishly
• sluggishness
• sluice
• sluice down
• sluice valve
• sluicegate
• sluiceway