1. Vigilant
   - on guard, upon one's guard, on your guard

See also: wary

• bakehouse
• Bakelite
• baker
• baker's dozen
• baker's eczema
• baker's yeast
• Bakersfield
• bakery
• bakeshop
• baking
• baking chocolate
• baking hot
• baking powder
• baking soda
• baking tray
• baking-powder biscuit
• Bakke decision
• baklava
• baksheesh
• bakshis
• bakshish
• Baku
• Bakunin
• Balaam
• balaclava