1 : a fact or event that affects a situation <Illness is the only circumstance that will excuse your absence.>
2 circumstances plural
: conditions at a certain time or place <Under the circumstances, I think we did well.>
3 circumstances plural
: the way something happens <Please explain the circumstances of the accident.>
4 circumstances plural
: the conditions in which someone lives <"When the Lord puts us in certain circumstances He doesn't mean for us to imagine them away." Lucy Maud Montgomery, Anne of Green Gables> He lives in easy circumstances.
5 : an uncontrollable event or situation <a victim of circumstance>