1. Very uncertain
   "left everything up in the air" 
2. Not yet determined
   "plans are still up in the air"

See also: uncertain

• Pinot grape
• Pinot noir
• pinpoint
• pinprick
• pins and needles
• pinscher
• Pinsk
• pinstripe
• pinstriped
• pint
• pint-size
• pint-sized
• pintado
• pintail
• Pinter
• pintle
• pinto
• pinto bean
• Pinus
• Pinus albicaulis
• Pinus aristata
• Pinus attenuata
• Pinus banksiana
• Pinus californiarum
• Pinus cembra