cir ‧ cum ‧ stan ‧ tial /ˌsɜːkəmˈstænʃ ə l◂ $ ˌsɜːr-/ BrE AmE adjective
1 . law based on something that appears to be true but is not proven
circumstantial evidence/case
The case against McCarthy is based largely on circumstantial evidence.
2 . formal including all the details:
The book includes a long and circumstantial account of Empson’s conversation with the Queen.
—circumstantially adverb