at-risk adjective 1at risk prepositional phrase 1forms 2 adjective1 •vulnerable, especially to abuse or delinquencyThe actual at-risk population was limited to those directly exposed and could be quarantined or monitored. at risk prepositional phrase1 •In a state or condition marked by a level of risk or vulnerability.The entire population initially seemed at risk of infection. formsmore at-risk · most at-risk