1. Vigilant
   "must remain on your guard in such a situation"
   - on guard, on one's guard, upon one's guard

See also: wary

• possible
• possible action
• possibleness
• possibly
• possum
• possum haw
• possum oak
• possumwood
• post
• post and lintel
• roofing paper
• roofing tile
• roofless
• rooftop
• rooftree
• roofy
• rooibos
• rooinek
• rook
• rookery
• rookie
• room
• room access
• room clerk
• room decorator