Unguarded/ʌnˈɡɑːrdɪd/ Definition 1 of 2Pro Tip 1/3Vulnerability Indicates a lack of security or defenses, often leading to potential risk or harm. The castle was unguarded, an easy target for the invaders. Pro Tip 2/3Negligence Can suggest someone's carelessness in leaving something unprotected or unsupervised. His unguarded smartphone was stolen from the coffee shop. Pro Tip 3/3Responsibility Used to highlight when someone should be taking care but isn't, often leading to blame. The unguarded chemicals posed a danger in the lab.