1. Open to doubt or suspicion
   - doubtful, dubious, dubitable, in question 
2. [archaic] Inspiring fear
   - formidable, redoubtable, unnerving

See also: alarming, questionable

• spin around
• spin bowler
• spin doctor
• spin drier
• spin dryer
• spin out
• spin the bottle
• spin the plate
• spin the platter
• spin-dry
• spin-off
• spina bifida
• spinach
• spinach beet
• spinach blight
• spinach mustard
• spinach plant
• Spinacia
• Spinacia oleracea
• spinal
• spinal accessory
• spinal anaesthesia
• spinal anaesthetic
• spinal anesthesia
• spinal anesthetic