cir·cum·stance / ˈsərkəmˌstans; -stəns/ • n. 1. (usu. circumstances) a fact or condition connected with or relevant to an event or action: we wanted to marry but circumstances didn't permit. ∎  an event or fact that causes or helps to cause something to happen, typically something undesirable: he was found dead but there were no suspicious circumstances | they were thrown together by circumstance. 2. one's state of financial or material welfare: living in reduced circumstances.PHRASES: under no circumstances never, whatever the situation is or might be.under (or in) the circumstances given the difficult nature of the situation: she had every right to be angry under the circumstances.DERIVATIVES: cir·cum·stanced adj.

circumstance (pl.) adjuncts of an action XIII; condition of affairs XIV; formality, ceremony; accessory matter, detail. — (O)F. circonstance, †circun- or L. circumstantia, f. prp. of circumstāre stand around, surround; see CIRCUM-, STAND.
Hence circumstantial XVI.