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

See also: wary

• accreditation
• accredited
• accrete
• accretion
• accretionary
• accretive
• accroides
• accroides gum
• accroides resin
• accrual
• accrual basis
• accrue
• accrued
• accruement
• acct.
• acculturate
• acculturation
• acculturational
• acculturative
• accumbent
• accumulate
• accumulated
• accumulation
• accumulative
• accumulator