1. Fully awake
   "so excited she was wide-awake all night"
   - unsleeping 
2. Fully alert and watchful
   - heads-up

See also: alert, awake, watchful

• pilgrimage
• piling
• Pilipino
• pill
• pill bottle
• pill bug
• pill head
• pill pusher
• pill roller
• pillage
• pillaged
• pillager
• pillaging
• pillar
• pillar box
• pillar of Islam
• pillar of strength
• pillar-box red
• pillar-shaped
• pillared
• Pillars of Hercules
• pillbox
• pillion
• pillock
• pillory